TY - JOUR A1 - Parry, Victor A1 - Schlägel, Ulrike E. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Behavioural Responses of Defended and Undefended Prey to Their Predator BT - A Case Study of Rotifera JF - Biology N2 - Predation is a strong species interaction causing severe harm or death to prey. Thus, prey species have evolved various defence strategies to minimize predation risk, which may be immediate (e.g., a change in behaviour) or transgenerational (morphological defence structures). We studied the behaviour of two strains of a rotiferan prey (Brachionus calyciflorus) that differ in their ability to develop morphological defences in response to their predator Asplanchna brightwellii. Using video analysis, we tested: (a) if two strains differ in their response to predator presence and predator cues when both are undefended; (b) whether defended individuals respond to live predators or their cues; and (c) if the morphological defence (large spines) per se has an effect on the swimming behaviour. We found a clear increase in swimming speed for both undefended strains in predator presence. However, the defended specimens responded neither to the predator presence nor to their cues, showing that they behave indifferently to their predator when they are defended. We did not detect an effect of the spines on the swimming behaviour. Our study demonstrates a complex plastic behaviour of the prey, not only in the presence of their predator, but also with respect to their defence status. KW - animal behaviour KW - transgenerational response KW - Brachionus calyciflorus KW - Asplanchna brightwellii KW - video analysis Y1 - 2022 U6 - https://doi.org/10.3390/biology11081217 SN - 2079-7737 VL - 11 IS - 8 PB - MDPI CY - Basel, Schweiz ER - TY - JOUR A1 - Parry, Victor A1 - Schlägel, Ulrike E. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Behavioural responses of defended and undefended prey to their predator BT - a case study of rotifera JF - Biology : open access journal N2 - Many animals that have to cope with predation have evolved mechanisms to reduce their predation risk. One of these mechanisms is change in morphology, for example, the development of spines. These spines are induced, when mothers receive chemical signals of a predator (kairomones) and their daughters are then equipped with defensive spines. We studied the behaviour of a prey and its predator when the prey is either defended or undefended. We used common aquatic micro-invertebrates, the rotifers Brachionus calyciflorus (prey) and Asplanchna brightwellii (predator) as experimental animals. We found that undefended prey increased its swimming speed in the presence of the predator. The striking result was that the defended prey did not respond to the predator's presence. This suggests that defended prey has a different response behaviour to a predator than undefended conspecifics. Our study provides further insights into complex zooplankton predator-prey interactions. Predation is a strong species interaction causing severe harm or death to prey. Thus, prey species have evolved various defence strategies to minimize predation risk, which may be immediate (e.g., a change in behaviour) or transgenerational (morphological defence structures). We studied the behaviour of two strains of a rotiferan prey (Brachionus calyciflorus) that differ in their ability to develop morphological defences in response to their predator Asplanchna brightwellii. Using video analysis, we tested: (a) if two strains differ in their response to predator presence and predator cues when both are undefended; (b) whether defended individuals respond to live predators or their cues; and (c) if the morphological defence (large spines) per se has an effect on the swimming behaviour. We found a clear increase in swimming speed for both undefended strains in predator presence. However, the defended specimens responded neither to the predator presence nor to their cues, showing that they behave indifferently to their predator when they are defended. We did not detect an effect of the spines on the swimming behaviour. Our study demonstrates a complex plastic behaviour of the prey, not only in the presence of their predator, but also with respect to their defence status. KW - animal behaviour KW - transgenerational response KW - Brachionus calyciflorus KW - Asplanchna brightwellii KW - video analysis Y1 - 2022 U6 - https://doi.org/10.3390/biology11081217 SN - 2079-7737 VL - 11 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Paraskevopoulou, Sofia A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Differential response to heat stress among evolutionary lineages of an aquatic invertebrate species complex JF - Biology letters N2 - Under global warming scenarios, rising temperatures can constitute heat stress to which species may respond differentially. Within a described species, knowledge on cryptic diversity is of further relevance, as different lineages/cryptic species may respond differentially to environmental change. The Brachionus calyciflorus species complex (Rotifera), which was recently described using integrative taxonomy, is an essential component of aquatic ecosystems. Here, we tested the hypothesis that these (formerly cryptic) species differ in their heat tolerance. We assigned 47 clones with nuclear ITS1 (nuITS1) and mitochondrial COI (mtCOI) markers to evolutionary lineages, now named B. calyciflorus sensu stricto (s.s.) and B. fernandoi. We selected 15 representative clones and assessed their heat tolerance as a bi-dimensional phenotypic trait affected by both the intensity and duration of heat stress. We found two distinct groups, with B. calyciflorus s.s. clones having higher heat tolerance than the novel species B. fernandoi. This apparent temperature specialization among former cryptic species underscores the necessity of a sound species delimitation and assignment, when organismal responses to environmental changes are investigated. KW - Brachionus calyciflorus KW - critical thermal maximum KW - cryptic species KW - ecological speciation KW - rotifers KW - heat tolerance Y1 - 2018 U6 - https://doi.org/10.1098/rsbl.2018.0498 SN - 1744-9561 SN - 1744-957X VL - 14 IS - 11 PB - Royal Society CY - London ER - TY - JOUR A1 - Paraskevopoulou, Sofia A1 - Dennis, Alice B. A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus rotifers JF - Scientific Reports N2 - Thermal stress response is an essential physiological trait that determines occurrence and temporal succession in nature, including response to climate change. We compared temperature-related demography in closely related heat-tolerant and heat-sensitive Brachionus rotifer species. We found significant differences in heat response, with the heat-sensitive species adopting a strategy of long survival and low population growth, while the heat-tolerant followed the opposite strategy. In both species, we examined the genetic basis of physiological variation by comparing gene expression across increasing temperatures. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Temperature induction caused opposing patterns of expression in further functional categories including energy, carbohydrate and lipid metabolism, and in genes related to ribosomal proteins. In the heat-sensitive species, elevated temperatures caused up-regulation of genes related to meiosis induction and post-translational histone modifications. This work demonstrates the sweeping reorganizations of biological functions that accompany temperature adaptation in these two species and reveals potential molecular mechanisms that might be activated for adaptation to global warming. KW - Ecology KW - Evolution KW - Oyster Crassostrea-gigas KW - cryptic species complex KW - pacific oyster KW - thermal-stress KW - genetic differentiation KW - expression patterns KW - molecular phylogeny KW - shock proteins KW - evolutionary KW - hsp70 Y1 - 2020 U6 - https://doi.org/10.1038/s41598-020-70173-0 SN - 2045-2322 VL - 10 PB - Macmillan Publishers Limited, part of Springer Nature CY - London ER - TY - JOUR A1 - Paraskevopoulou, Sofia A1 - Dennis, Alice B. A1 - Weithoff, Guntram A1 - Hartmann, Stefanie A1 - Tiedemann, Ralph T1 - Within species expressed genetic variability and gene expression response to different temperatures in the rotifer Brachionus calyciflorus sensu stricto JF - PLoS ONE N2 - Genetic divergence is impacted by many factors, including phylogenetic history, gene flow, genetic drift, and divergent selection. Rotifers are an important component of aquatic ecosystems, and genetic variation is essential to their ongoing adaptive diversification and local adaptation. In addition to coding sequence divergence, variation in gene expression may relate to variable heat tolerance, and can impose ecological barriers within species. Temperature plays a significant role in aquatic ecosystems by affecting species abundance, spatio-temporal distribution, and habitat colonization. Recently described (formerly cryptic) species of the Brachionus calyciflorus complex exhibit different temperature tolerance both in natural and in laboratory studies, and show that B. calyciflorus sensu stricto (s.s.) is a thermotolerant species. Even within B. calyciflorus s.s., there is a tendency for further temperature specializations. Comparison of expressed genes allows us to assess the impact of stressors on both expression and sequence divergence among disparate populations within a single species. Here, we have used RNA-seq to explore expressed genetic diversity in B. calyciflorus s.s. in two mitochondrial DNA lineages with different phylogenetic histories and differences in thermotolerance. We identify a suite of candidate genes that may underlie local adaptation, with a particular focus on the response to sustained high or low temperatures. We do not find adaptive divergence in established candidate genes for thermal adaptation. Rather, we detect divergent selection among our two lineages in genes related to metabolism (lipid metabolism, metabolism of xenobiotics). Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0223134 SN - 1932-6203 VL - 9 IS - 14 PB - PLoS ONE CY - San Francisco, California ER - TY - JOUR A1 - Padur, Lisa A1 - Wedekind, Juliane A1 - Öztürk, Öznur A1 - Streit, Bruno A1 - Tiedemann, Ralph A1 - Plath, Martin T1 - Do audience effects lead to relaxed male sexual harassment? N2 - Several recent studies reported on so-called audience effects in male Atlantic mollies (Poecilia mexicana), in which the visual presence of a potential rival affects male sexual activity. We asked whether and how audience effects interact with male sexual harassment. Poecilia mexicana almost constantly attempt to mate, while females are mostly non- responsive to male approaches. Females flee from this sexual harassment and, thus, are more vigilant in the presence of males, so females may have hampered feeding opportunities. Do audience effects lead to altered male sexual harassment? Focal females were given an opportunity to feed in the presence of a male or a female partner and the difference in feeding times was interpreted as an effect caused by male harassment. Tests were conducted without an audience (1), or an audience male was visually presented either directly inside the test tank (2), or further away (in an adjoining compartment (3)). We found that levels of pre-mating behaviour did not vary significantly among treatments, but males exhibited more copulation attempts (thrusting) in treatment (3), suggesting that males respond to increased risk of sperm competition with higher sperm expenditure. Females fed less (and started feeding later) when a harassing partner male was around, and this effect was not dependent on the audience treatment, but, overall, females spent more time feeding (and started feeding earlier) when an audience was presented. Hence, feeding time reductions appear to be independent of audience effects, but perceived 'safety in numbers' may lead to increased foraging in larger groups. Y1 - 2009 UR - http://brill.publisher.ingentaconnect.com/content/brill/beh U6 - https://doi.org/10.1163/000579509x12483520922124 SN - 0005-7959 ER - TY - JOUR A1 - Nguyen, Manh Duy Linh A1 - Mamonekene, Victor A1 - Vater, Marianne A1 - Bartsch, Peter A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Ontogeny of electric organ and electric organ discharge in Campylomormyrus rhynchophorus (Teleostei: Mormyridae) JF - Journal of comparative physiology; A, Neuroethology, sensory, neural, and behavioral physiology N2 - The aim of this study was a longitudinal description of the ontogeny of the adult electric organ of Campylomormyrus rhynchophorus which produces as adult an electric organ discharge of very long duration (ca. 25 ms). We could indeed show (for the first time in a mormyrid fish) that the electric organ discharge which is first produced early during ontogeny in 33-mm-long juveniles is much shorter in duration and has a different shape than the electric organ discharge in 15-cm-long adults. The change from this juvenile electric organ discharges into the adult electric organ discharge takes at least a year. The increase in electric organ discharge duration could be causally linked to the development of surface evaginations, papillae, at the rostral face of the electrocyte which are recognizable for the first time in 65-mm-long juveniles and are most prominent at the periphery of the electrocyte. KW - Weakly electric fish KW - Development KW - Electric organ discharge KW - Electric KW - organ KW - Electrocyte features Y1 - 2020 U6 - https://doi.org/10.1007/s00359-020-01411-z SN - 0340-7594 SN - 1432-1351 VL - 206 IS - 3 SP - 453 EP - 466 PB - Springer CY - Berlin ; Heidelberg ER - TY - GEN A1 - Neye, Gundula A1 - Wallschläger, Hans-Dieter A1 - Tiedemann, Ralph T1 - Song dialect boundaries in the Yellowhammer: Do they restrict gene flow? T2 - Journal of ornithology Y1 - 2006 SN - 0021-8375 VL - 147 IS - Supplement 1 SP - 219 EP - 219 PB - Blackwell CY - New York ER - TY - JOUR A1 - Nahavandi, Nahid A1 - Plath, Martin A1 - Tiedemann, Ralph A1 - Mirzajani, Ali R. T1 - Sexual and natural selection on morphological traits in a marine amphipod, Pontogammarus maeoticus (Sowinsky, 1894) JF - Marine biology research N2 - Sexual selection often leads to sexual dimorphism, where secondary sexual traits are more expressed in the male sex. This may be due, for example, to increased fighting or mate-guarding abilities of males expressing those traits. We investigated sexually dimorphic traits in four populations of a marine amphipod, Pontogammarus maeoticus (Gammaridea: Pontogammaridae), the most abundant amphipod species in the sublittoral zone along the southern shoreline of the Caspian Sea. Male amphipods are typically larger in body size than females, and have relatively larger posterior gnathopods and antennae. However, it remains to be studied for most other body appendages whether or not, and to what extent, they are sexually dimorphic. Using Analysis of Covariance (ANCOVA), we compared the relationships between body size and trait expression for 35 metric characters between males and females, and among the four populations examined by performing three different Discriminant Function Analyses (DFA). We detected several thus far undescribed sexual dimorphic traits such as the seventh peraeopods or the epimeral plates. We also found that the size of the propodus of the first and second gnathopods increases with increasing body size, and this allometric increase was stronger in males than in females. Finally, we found that the degree of sexual dimorphism in the expression of the width of the third epimeral plate varies across sites, suggesting that differences in ecology might affect the strength of sexual selection in different populations. KW - Caspian Sea KW - crustacean KW - dimorphism KW - scramble competition Y1 - 2011 U6 - https://doi.org/10.1080/17451001003713589 SN - 1745-1000 VL - 7 IS - 2 SP - 135 EP - 146 PB - Taylor & Francis Group CY - Oslo ER - TY - JOUR A1 - Nahavandi, Nahid A1 - Ketmaier, Valerio A1 - Tiedemann, Ralph T1 - Intron structure of the elongation factor 1-alpha gene in the ponto-caspian amphipod pontogammarus maeoticus (Sowinsky, 1894) and its phylogeographic utility JF - Journal of crustacean biology N2 - We tested the utility of a 230 base pair intron fragment of the highly conserved nuclear gene Elongation Factor 1-alpha (EF1-alpha) as a proper marker to reconstruct the phylogeography of the marine amphipod Pontogammarus maeoticus (Sowinsky, 1894) from the Caspian and Black Seas. As a prerequisite for further analysis, we confirmed by Southern blot analysis that EF1-alpha is encoded at a single locus in P. maeoticus. We included 15 populations and 60 individuals in the study. Both the phylogeny of the 27 unique alleles found and population genetic analyses revealed a significant differentiation between populations from the aforementioned sea basins. Our results are in remarkable agreement with recent studies on a variety of species from the same area, which invariably support a major phylogeographic break between the Caspian and Black Seas. We thus conclude that our EF1-alpha intron is an informative marker for phylogeographic studies in amphipods at the shallow population level. KW - Amphipoda KW - Elongation Factor 1-alpha KW - phylogeography KW - Ponto-Caspian region KW - Pontogammarus maeoticus Y1 - 2012 U6 - https://doi.org/10.1163/193724012X626584 SN - 0278-0372 VL - 32 IS - 3 SP - 425 EP - 433 PB - Brill CY - San Antonio ER - TY - JOUR A1 - Nahavandi, Nahid A1 - Ketmaier, Valerio A1 - Plath, Martin A1 - Tiedemann, Ralph T1 - Diversification of Ponto-Caspian aquatic fauna - morphology and molecules retrieve congruent evolutionary relationships in Pontogammarus maeoticus (Amphipoda: Pontogammaridae) JF - Molecular phylogenetics and evolution N2 - The geological history of the Ponto-Caspian region, with alternating cycles of isolation and reconnection among the three main basins (Black and Azov Seas, and the more distant Caspian Sea) as well as between them and the Mediterranean Sea, profoundly affected the diversification of its aquatic fauna, leading to a high degree of endemism. Two alternative hypotheses on the origin of this amazing biodiversity have been proposed, corresponding to phases of allopatric separation of aquatic fauna among sea basins: a Late Miocene origin (10-6 MYA) vs. a more recent Pleistocene ancestry (<2 MYA). Both hypotheses support a vicariant origin of (1) Black + Azov Sea lineages on the one hand, and (2) Caspian Sea lineages on the other. Here, we present a study on the Ponto-Caspian endemic amphipod Pontogammarus maeoticus. We assessed patterns of divergence based on (a) two mitochondrial and one nuclear gene, and (b) a morphometric analysis of 23 morphological traits in 16 populations from South and West Caspian Sea, South Azov Sea and North-West Black Sea. Genetic data indicate a long and independent evolutionary history, dating back from the late Miocene to early Pleistocene (6.6-1.6 MYA), for an unexpected, major split between (i) a Black Sea clade and (ii) a well-supported clade grouping individuals from the Caspian and Azov Seas. Absence of shared haplotypes argues against either recent or human-mediated exchanges between Caspian and Azov Seas. A mismatch distribution analysis supports more stable population demography in the Caspian than in the Black Sea populations. Morphological divergence largely followed patterns of genetic divergence: our analyses grouped samples according to the basin of origin and corroborated the close phylogenetic affinity between Caspian and Azov Sea lineages. Altogether, our results highlight the necessity of careful (group-specific) evaluation of evolutionary trajectories in marine taxa that should certainly not be inferred from the current geographical proximity of sea basins alone. (C) 2013 Elsevier Inc. All rights reserved. KW - Biodiversity hotspot KW - Black Sea KW - Caspian Sea KW - Paratethys KW - Sea of Azov KW - Vicariance Y1 - 2013 U6 - https://doi.org/10.1016/j.ympev.2013.05.021 SN - 1055-7903 SN - 1095-9513 VL - 69 IS - 3 SP - 1063 EP - 1076 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Nagel, Rebecca A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - Electric organ discharge diversification in mormyrid weakly electric fish is associated with differential expression of voltage-gated ion channel genes JF - Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology N2 - In mormyrid weakly electric fish, the electric organ discharge (EOD) is used for species recognition, orientation and prey localization. Produced in the muscle-derived adult electric organ, the EOD exhibits a wide diversity across species in both waveform and duration. While certain defining EOD characteristics can be linked to anatomical features of the electric organ, many factors underlying EOD differentiation are yet unknown. Here, we report the differential expression of 13 Kv1 voltage-gated potassium channel genes, two inwardly rectifying potassium channel genes, two previously studied sodium channel genes and an ATPase pump in two sympatric species of the genus Campylomormyrus in both the adult electric organ and skeletal muscle. Campylomormyrus compressirostris displays a basal EOD, largely unchanged during development, while C. tshokwe has an elongated, putatively derived discharge. We report an upregulation in all Kv1 genes in the electric organ of Campylomormyrus tshokwe when compared to both skeletal muscle and C. compressirostris electric organ. This pattern of upregulation in a species with a derived EOD form suggests that voltage-gated potassium channels are potentially involved in the diversification of the EOD signal among mormyrid weakly electric fish. KW - Weakly electric fish KW - Ion channels KW - Electric organ KW - Gene expression KW - Campylomormyrus Y1 - 2017 U6 - https://doi.org/10.1007/s00359-017-1151-2 SN - 0340-7594 SN - 1432-1351 VL - 203 SP - 183 EP - 195 PB - Springer CY - New York ER - TY - JOUR A1 - Nagel, Rebecca A1 - Kirschbaum, Frank A1 - Hofmann, Volker A1 - Engelmann, Jacob A1 - Tiedemann, Ralph T1 - Electric pulse characteristics can enable species recognition in African weakly electric fish species JF - Scientific Reports N2 - Communication is key to a wide variety of animal behaviours and multiple modalities are often involved in this exchange of information from sender to receiver. The communication of African weakly electric fish, however, is thought to be predominantly unimodal and is mediated by their electric sense, in which species-specific electric organ discharges (EODs) are generated in a context-dependent and thus variable sequence of pulse intervals (SPI). While the primary function of the electric sense is considered to be electrolocation, both of its components likely carry information regarding identity of the sender. However, a clear understanding of their contribution to species recognition is incomplete. We therefore analysed these two electrocommunication components (EOD waveform and SPI statistics) in two sympatric mormyrid Campylomormyrus species. In a set of five playback conditions, we further investigated which components may drive interspecific recognition and discrimination. While we found that both electrocommunication components are species-specific, the cues necessary for species recognition differ between the two species studied. While the EOD waveform and SPI were both necessary and sufficient for species recognition in C. compressirostris males, C. tamandua males apparently utilize other, non-electric modalities. Mapped onto a recent phylogeny, our results suggest that discrimination by electric cues alone may be an apomorphic trait evolved during a recent radiation in this taxon. KW - Dwelling Atlantic Mollies KW - Organ Discharge Patterns KW - Mormyrid Fish KW - Pollimyrus-Isidori KW - Acoustic-Signals KW - Sexual Selection KW - Phylogenetic-Relationships KW - Hypopomus-Occidentalis KW - Convergent Evolution KW - Poecili-Mexicana Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-29132-z SN - 2045-2322 VL - 8 SP - 1 EP - 12 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Milinkovitch, Michel C. A1 - Kanitz, Ricardo A1 - Tiedemann, Ralph A1 - Tapia, Washington A1 - Llerena, Fausto A1 - Caccone, Adalgisa A1 - Gibbs, James P. A1 - Powell, Jeffrey R. T1 - Recovery of a nearly extinct Galapagos tortoise despite minimal genetic variation JF - Evolutionary applications N2 - A species of Galapagos tortoise endemic to Espanola Island was reduced to just 12 females and three males that have been bred in captivity since 1971 and have produced over 1700 offspring now repatriated to the island. Our molecular genetic analyses of juveniles repatriated to and surviving on the island indicate that none of the tortoises sampled in 1994 had hatched on the island versus 3% in 2004 and 24% in 2007, which demonstrates substantial and increasing reproduction in situ once again. This recovery occurred despite the parental population having an estimated effective population size <8 due to a combination of unequal reproductive success of the breeders and nonrandom mating in captivity. These results provide guidelines for adapting breeding regimes in the parental captive population and decreasing inbreeding in the repatriated population. Using simple morphological data scored on the sampled animals, we also show that a strongly heterogeneous distribution of tortoise sizes on Espanola Island observed today is due to a large variance in the number of animals included in yearly repatriation events performed in the last 40years. Our study reveals that, at least in the short run, some endangered species can recover dramatically despite a lack of genetic variation and irregular repatriation efforts. KW - captive populations KW - conservation biology KW - conservation genetics Y1 - 2013 U6 - https://doi.org/10.1111/eva.12014 SN - 1752-4571 VL - 6 IS - 2 SP - 377 EP - 383 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Milinkovitch, M. C. A1 - Monteyne, D. A1 - Gibbs, J. P. A1 - Fritts, T. H. A1 - Tapia, W. A1 - Snell, H. L. A1 - Tiedemann, Ralph A1 - Caccone, Adalgisa A1 - Powell, J. R. T1 - Genetic analysis of a successful repatriation programme : giant Galapagos tortoises N2 - As natural populations of endangered species dwindle to precarious levels, remaining members are sometimes brought into captivity, allowed to breed and their offspring returned to the natural habitat. One goal of such repatriation programmes is to retain as much of the genetic variation of the species as possible. A taxon of giant GalApagos tortoises on the island of Espahola has been the subject of a captive breeding-repatriation programme for 33 years. Core breeders, consisting of 12 females and three males, have produced more than 1200 offspring that have been released on Espanola where in situ reproduction has recently been observed. Using microsatellite DNA markers, we have determined the maternity and paternity of 132 repatriated offspring. Contributions of the breeders are highly skewed. This has led to a further loss of genetic variation that is detrimental to the long-term survival of the population. Modifications to the breeding programme could alleviate this problem Y1 - 2004 SN - 0962-8452 ER - TY - JOUR A1 - Marrone, F. A1 - Havenstein, Katja A1 - Tiedemann, Ralph A1 - Ketmaier, V. T1 - Identification and characterization of five polymorphic microsatellite loci in the freshwater copepod Hemidiaptomus gurneyi (Copepoda: Calanoida: Diaptomidae) JF - The Italian journal of zoology N2 - Hemidiaptomus diaptomid copepods are known to be excellent biological indicators for the highly biodiverse crustacean communities inhabiting Mediterranean temporary ponds (MTPs), an endangered inland water habitat whose conservation is considered a priority according to the "Habitat Directive" of the European Union. This study reports on the characterization of five polymorphic microsatellite loci in Hemidiaptomus gurneyi, to be used as markers for fine-scale studies on the population genetic structure and metapopulation dynamics of a typical and obligate MTP dweller. The five selected loci proved to be polymorphic in the species, with three to five polymorphic loci per studied population. Overall, mean heterozygosity scored for all loci and populations was lower than that reported for the few other diaptomid species for which microsatellite loci have been to date described; this is possibly due to the intrinsically fragmented and isolated peculiar habitat inhabited by the species. Furthermore, the presence of indels within the flanking regions of selected loci was scored. This study, albeit confirming the technical difficulties in finding proper microsatellite markers in copepods, provides for the first time a set of useful polymorphic microsatellite loci for a Hemidiaptomus species, thus allowing the realization of fine-scale phylogeographic and population genetics studies of this flagship crustacean taxon for MTPs. KW - Mediterranean temporary ponds KW - diaptomid copepods KW - SSRs Y1 - 2016 U6 - https://doi.org/10.1080/11250003.2015.1126363 SN - 1125-0003 SN - 1748-5851 VL - 83 SP - 146 EP - 150 PB - Springer CY - Abingdon ER - TY - JOUR A1 - Makowicz, Amber M. A1 - Tiedemann, Ralph A1 - Steele, Rachel N. A1 - Schlupp, Ingo T1 - Kin Recognition in a Clonal Fish, Poecilia formosa JF - PLoS one N2 - Relatedness strongly influences social behaviors in a wide variety of species. For most species, the highest typical degree of relatedness is between full siblings with 50% shared genes. However, this is poorly understood in species with unusually high relatedness between individuals: clonal organisms. Although there has been some investigation into clonal invertebrates and yeast, nothing is known about kin selection in clonal vertebrates. We show that a clonal fish, the Amazon molly (Poecilia formosa), can distinguish between different clonal lineages, associating with genetically identical, sister clones, and use multiple sensory modalities. Also, they scale their aggressive behaviors according to the relatedness to other females: they are more aggressive to non-related clones. Our results demonstrate that even in species with very small genetic differences between individuals, kin recognition can be adaptive. Their discriminatory abilities and regulation of costly behaviors provides a powerful example of natural selection in species with limited genetic diversity. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0158442 SN - 1932-6203 VL - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Mahler, B. A1 - Schneider, A. R. R. A1 - Di Giacomo, A. S. A1 - Di Giacomo, A. G. A1 - Reboreda, Juan C. A1 - Tiedemann, Ralph T1 - Microsatellite usefulness is independent of phylogenetic distance in Tyrant flycatchers (Aves: Tyrannidae) - a test using two globally threatened species JF - Genetics and molecular research N2 - Tyrant flycatchers (Aves: Tyrannidae) are endemic to the New World, and many species of this group are threatened or near-threatened at the global level. The aim of this study was to test the 18 microsatellite markers that have been published for other Tyrant flycatchers in the Strange-tailed Tyrant (Alectrurus risora) and the Sharp-tailed Tyrant (Culicivora caudacuta), two endemic species of southern South American grasslands that are classified as vulnerable. We also analyzed the usefulness of loci in relation to phylogenetic distance to the source species. Amplification success was high in both species (77 to 83%) and did not differ between the more closely and more distantly related species to the source species. Polymorphism success was also similar for both species, with 9 and 8 loci being polymorphic, respectively. An increased phylogenetic distance thus does not gradually lead to allelic or locus dropouts, implying that in Tyrant flycatchers, the published loci are useful independent of species relatedness. KW - Alectrurus risora KW - Culicivora caudacuta KW - Microsatellites KW - Tyrannidae Y1 - 2013 U6 - https://doi.org/10.4238/2013.August.12.12 SN - 1676-5680 VL - 12 IS - 3 SP - 2966 EP - 2972 PB - FUNPEC CY - Ribeirao Preto ER - TY - JOUR A1 - Lamanna, Francesco A1 - Kirschbaum, Frank A1 - Waurick, Isabelle A1 - Dieterich, Christoph A1 - Tiedemann, Ralph T1 - Cross-tissue and cross-species analysis of gene expression in skeletal muscle and electric organ of African weakly-electric fish (Teleostei; Mormyridae) JF - BMC genomics N2 - Background: African weakly-electric fishes of the family Mormyridae are able to produce and perceive weak electric signals (typically less than one volt in amplitude) owing to the presence of a specialized, muscle-derived electric organ (EO) in their tail region. Such electric signals, also known as Electric Organ Discharges (EODs), are used for objects/prey localization, for the identification of conspecifics, and in social and reproductive behaviour. This feature might have promoted the adaptive radiation of this family by acting as an effective pre-zygotic isolation mechanism. Despite the physiological and evolutionary importance of this trait, the investigation of the genetic basis of its function and modification has so far remained limited. In this study, we aim at: i) identifying constitutive differences in terms of gene expression between electric organ and skeletal muscle (SM) in two mormyrid species of the genus Campylomormyrus: C. compressirostris and C. tshokwe, and ii) exploring cross-specific patterns of gene expression within the two tissues among C. compressirostris, C. tshokwe, and the outgroup species Gnathonemus petersii. Results: Twelve paired-end (100 bp) strand-specific RNA-seq Illumina libraries were sequenced, producing circa 330 M quality-filtered short read pairs. The obtained reads were assembled de novo into four reference transcriptomes. In silico cross-tissue DE-analysis allowed us to identify 271 shared differentially expressed genes between EO and SM in C. compressirostris and C. tshokwe. Many of these genes correspond to myogenic factors, ion channels and pumps, and genes involved in several metabolic pathways. Cross-species analysis has revealed that the electric organ transcriptome is more variable in terms of gene expression levels across species than the skeletal muscle transcriptome. Conclusions: The data obtained indicate that: i) the loss of contractile activity and the decoupling of the excitation-contraction processes are reflected by the down-regulation of the corresponding genes in the electric organ's transcriptome; ii) the metabolic activity of the EO might be specialized towards the production and turn-over of membrane structures; iii) several ion channels are highly expressed in the EO in order to increase excitability; iv) several myogenic factors might be down-regulated by transcription repressors in the EO. Y1 - 2015 U6 - https://doi.org/10.1186/s12864-015-1858-9 SN - 1471-2164 VL - 16 PB - BioMed Central CY - London ER - TY - JOUR A1 - Lamanna, Francesco A1 - Kirschbaum, Frank A1 - Waurick, Isabelle A1 - Dieterich, Christoph A1 - Tiedemann, Ralph T1 - Cross-tissue and cross-species analysis of gene expression in skeletal muscle and electric organ of African weakly-electric fish (Teleostei; Mormyridae) JF - BMC Genomics N2 - Background African weakly-electric fishes of the family Mormyridae are able to produce and perceive weak electric signals (typically less than one volt in amplitude) owing to the presence of a specialized, muscle-derived electric organ (EO) in their tail region. Such electric signals, also known as Electric Organ Discharges (EODs), are used for objects/prey localization, for the identification of conspecifics, and in social and reproductive behaviour. This feature might have promoted the adaptive radiation of this family by acting as an effective pre-zygotic isolation mechanism. Despite the physiological and evolutionary importance of this trait, the investigation of the genetic basis of its function and modification has so far remained limited. In this study, we aim at: i) identifying constitutive differences in terms of gene expression between electric organ and skeletal muscle (SM) in two mormyrid species of the genus Campylomormyrus: C. compressirostris and C. tshokwe, and ii) exploring cross-specific patterns of gene expression within the two tissues among C. compressirostris, C. tshokwe, and the outgroup species Gnathonemus petersii. Results Twelve paired-end (100 bp) strand-specific RNA-seq Illumina libraries were sequenced, producing circa 330 M quality-filtered short read pairs. The obtained reads were assembled de novo into four reference transcriptomes. In silico cross-tissue DE-analysis allowed us to identify 271 shared differentially expressed genes between EO and SM in C. compressirostris and C.tshokwe. Many of these genes correspond to myogenic factors, ion channels and pumps, and genes involved in several metabolic pathways. Cross-species analysis has revealed that the electric organ transcriptome is more variable in terms of gene expression levels across species than the skeletal muscle transcriptome. Conclusions The data obtained indicate that: i) the loss of contractile activity and the decoupling of the excitation-contraction processes are reflected by the down-regulation of the corresponding genes in the electric organ’s transcriptome; ii) the metabolic activity of the EO might be specialized towards the production and turn-over of membrane structures; iii) several ion channels are highly expressed in the EO in order to increase excitability; iv) several myogenic factors might be down-regulated by transcription repressors in the EO. Y1 - 2015 U6 - https://doi.org/10.1186/s12864-015-1858-9 SN - 1471-2164 VL - 16 IS - 668 PB - Biomed Central CY - London ER - TY - JOUR A1 - Lamanna, Francesco A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - De novo assembly and characterization of the skeletal muscle and electric organ transcriptomes of the African weakly electric fish Campylomormyrus compressirostris (Mormyridae, Teleostei) JF - Molecular ecology resources N2 - African weakly electric fishes (Mormyridae) underwent an outstanding adaptive radiation (about 200 species), putatively owing to their ability to communicate through species-specific weak electric signals. The electric organ discharge (EOD) is produced by muscle-derived electrocytes organized in piles to form an electric organ. Despite the importance of this trait as a prezygotic isolation mechanism, genomic resources remained limited. We present here a first draft of the skeletal muscle and electric organ transcriptomes from the weakly electric fish species Campylomormyrus compressirostris, obtained using the Illumina HiSeq2000 sequencing technology. Approximately 6.8 Gbp of cDNA sequence data were produced from both tissues, resulting in 57268109 raw reads for the skeletal muscle and 46934923 for the electric organ, and assembled de novo into 46143 and 89270 contigs, respectively. About 50% of both transcriptomes were annotated after protein databases search. The two transcriptomes show similar profiles in terms of Gene Ontology categories composition. We identified several candidate genes which are likely to play a central role in the production and evolution of the electric signal. For most of these genes, and for many other housekeeping genes, we were able to obtain the complete or partial coding DNA sequences (CDS), which can be used for the development of primers to be utilized in qRT-PCR experiments. We present also the complete mitochondrial genome and compare it to those available from other weakly electric fish species. Additionally, we located 1671 SSR-containing regions with their flanking sites and designed the relative primers. This study establishes a first step in the development of genomic tools aimed at understanding the role of electric communication during speciation. KW - cSSR KW - electric fish KW - electric organ KW - skeletal muscle KW - transcriptome Y1 - 2014 U6 - https://doi.org/10.1111/1755-0998.12260 SN - 1755-098X SN - 1755-0998 VL - 14 IS - 6 SP - 1222 EP - 1230 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Lamanna, Francesco A1 - Kirschbaum, Frank A1 - Ernst, Anja R. R. A1 - Feulner, Philine G. D. A1 - Mamonekene, Victor A1 - Paul, Christiane A1 - Tiedemann, Ralph T1 - Species delimitation and phylogenetic relationships in a genus of African weakly-electric fishes (Osteoglossiformes, Mormyridae, Campylomormyrus) JF - Molecular phylogenetics and evolution N2 - African weakly-electric fishes (Mormyridae) are able to communicate through species-specific electric signals; this feature might have favoured the evolutionary radiation observed in this family (over 200 species) by acting as an effective pre-zygotic isolation mechanism. In the present study we used mitochondria((cytb) and nuclear (rps7, scn4aa) markers in order to reconstruct a species-phylogeny and identify species boundaries for the genus Campylomormyrus, by applying inference methods based on the multispecies coalescent model. Additionally, we employed 16 microsatellite markers, landmark-based morphometric measurements, and electro-physiological analyses as independent lines of evidence to the results obtained from the sequence data. The results show that groups that are morphologically different are also significantly divergent at the genetic level, whereas morphologically similar groups, displaying dissimilar electric signals, do not show enough genetic diversity to be considered separate species. Furthermore, the data confirm the presence of a yet undescribed species within the genus Campylomormyrus. (C) 2016 Elsevier Inc. All rights reserved. KW - Mormyridae KW - Multispecies-coalescent KW - Campylomormyrus KW - Geometric morphometrics KW - Microsatellites KW - Species-delimitation Y1 - 2016 U6 - https://doi.org/10.1016/j.ympev.2016.04.035 SN - 1055-7903 SN - 1095-9513 VL - 101 SP - 8 EP - 18 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Lah, Ljerka A1 - Trense, Daronja A1 - Benke, Harald A1 - Berggren, Per A1 - Gunnlaugsson, Þorvaldur A1 - Lockyer, Christina A1 - Öztürk, Ayaka A1 - Öztürk, Bayram A1 - Pawliczka, Iwona A1 - Roos, Anna A1 - Siebert, Ursula A1 - Skóra, Krzysztof A1 - Víkingsson, Gísli A1 - Tiedemann, Ralph T1 - Spatially Explicit Analysis of Genome-Wide SNPs Detects Subtle Population Structure in a Mobile Marine Mammal, the Harbor Porpoise JF - PLoS one N2 - The population structure of the highly mobile marine mammal, the harbor porpoise (Phocoena phocoena), in the Atlantic shelf waters follows a pattern of significant isolation-by-distance. The population structure of harbor porpoises from the Baltic Sea, which is connected with the North Sea through a series of basins separated by shallow underwater ridges, however, is more complex. Here, we investigated the population differentiation of harbor porpoises in European Seas with a special focus on the Baltic Sea and adjacent waters, using a population genomics approach. We used 2872 single nucleotide polymorphisms (SNPs), derived from double digest restriction-site associated DNA sequencing (ddRAD-seq), as well as 13 microsatellite loci and mitochondrial haplotypes for the same set of individuals. Spatial principal components analysis (sPCA), and Bayesian clustering on a subset of SNPs suggest three main groupings at the level of all studied regions: the Black Sea, the North Atlantic, and the Baltic Sea. Furthermore, we observed a distinct separation of the North Sea harbor porpoises from the Baltic Sea populations, and identified splits between porpoise populations within the Baltic Sea. We observed a notable distinction between the Belt Sea and the Inner Baltic Sea sub-regions. Improved delineation of harbor porpoise population assignments for the Baltic based on genomic evidence is important for conservation management of this endangered cetacean in threatened habitats, particularly in the Baltic Sea proper. In addition, we show that SNPs outperform microsatellite markers and demonstrate the utility of RAD-tags from a relatively small, opportunistically sampled cetacean sample set for population diversity and divergence analysis. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0162792 SN - 1932-6203 VL - 11 IS - 10 PB - PLoS CY - Lawrence, Kan. ER - TY - JOUR A1 - Lah, Ljerka A1 - Trense, Daronja A1 - Benke, Harald A1 - Berggren, Per A1 - Gunnlaugsson, Porvaldur A1 - Lockyer, Christina A1 - Öztürk, Ayaka A1 - Öztürk, Bayram A1 - Pawliczka, Iwona A1 - Roos, Anna A1 - Siebert, Ursula A1 - Skora, Krzysztof A1 - Vikingsson, Gisli A1 - Tiedemann, Ralph T1 - Spatially Explicit Analysis of Genome-Wide SNPs Detects Subtle Population Structure in a Mobile Marine Mammal, the Harbor Porpoise JF - PLoS one N2 - The population structure of the highly mobile marine mammal, the harbor porpoise (Phocoena phocoena), in the Atlantic shelf waters follows a pattern of significant isolation-by-distance. The population structure of harbor porpoises from the Baltic Sea, which is connected with the North Sea through a series of basins separated by shallow underwater ridges, however, is more complex. Here, we investigated the population differentiation of harbor porpoises in European Seas with a special focus on the Baltic Sea and adjacent waters, using a population genomics approach. We used 2872 single nucleotide polymor-phisms (SNPs), derived from double digest restriction-site associated DNA sequencing (ddRAD-seq), as well as 13 microsatellite loci and mitochondrial haplotypes for the same set of individuals. Spatial principal components analysis (sPCA), and Bayesian clustering on a subset of SNPs suggest three main groupings at the level of all studied regions: the Black Sea, the North Atlantic, and the Baltic Sea. Furthermore, we observed a distinct separation of the North Sea harbor porpoises from the Baltic Sea populations, and identified splits between porpoise populations within the Baltic Sea. We observed a notable distinction between the Belt Sea and the Inner Baltic Sea sub-regions. Improved delineation of harbor porpoise population assignments for the Baltic based on genomic evidence is important for conservation management of this endangered cetacean in threatened habitats, particularly in the Baltic Sea proper. In addition, we show that SNPs outperform microsatellite markers and demonstrate the utility of RAD-tags from a relatively small, opportunistically sampled cetacean sample set for population diversity and divergence analysis. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0162792 SN - 1932-6203 VL - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Krüger, Johanna A1 - Foerster, Verena Elisabeth A1 - Trauth, Martin H. A1 - Hofreiter, Michael A1 - Tiedemann, Ralph T1 - Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core JF - Frontiers in Earth Science N2 - Eastern Africa has been a prime target for scientific drilling because it is rich in key paleoanthropological sites as well as in paleolakes, containing valuable paleoclimatic information on evolutionary time scales. The Hominin Sites and Paleolakes Drilling Project (HSPDP) explores these paleolakes with the aim of reconstructing environmental conditions around critical episodes of hominin evolution. Identification of biological taxa based on their sedimentary ancient DNA (sedaDNA) traces can contribute to understand past ecological and climatological conditions of the living environment of our ancestors. However, sedaDNA recovery from tropical environments is challenging because high temperatures, UV irradiation, and desiccation result in highly degraded DNA. Consequently, most of the DNA fragments in tropical sediments are too short for PCR amplification. We analyzed sedaDNA in the upper 70 m of the composite sediment core of the HSPDP drill site at Chew Bahir for eukaryotic remnants. We first tested shotgun high throughput sequencing which leads to metagenomes dominated by bacterial DNA of the deep biosphere, while only a small fraction was derived from eukaryotic, and thus probably ancient, DNA. Subsequently, we performed cross-species hybridization capture of sedaDNA to enrich ancient DNA (aDNA) from eukaryotic remnants for paleoenvironmental analysis, using established barcoding genes (cox1 and rbcL for animals and plants, respectively) from 199 species that may have had relatives in the past biosphere at Chew Bahir. Metagenomes yielded after hybridization capture are richer in reads with similarity to cox1 and rbcL in comparison to metagenomes without prior hybridization capture. Taxonomic assignments of the reads from these hybridization capture metagenomes also yielded larger fractions of the eukaryotic domain. For reads assigned to cox1, inferred wet periods were associated with high inferred relative abundances of putative limnic organisms (gastropods, green algae), while inferred dry periods showed increased relative abundances for insects. These findings indicate that cross-species hybridization capture can be an effective approach to enhance the information content of sedaDNA in order to explore biosphere changes associated with past environmental conditions, enabling such analyses even under tropical conditions. KW - Chew Bahir KW - hybridization capture KW - ICDP KW - paleoclimate KW - past biosphere KW - sedaDNA KW - sediment core Y1 - 2021 U6 - https://doi.org/10.3389/feart.2021.683010 SN - 2296-6463 SP - 1 EP - 20 PB - Frontiers in Earth Science CY - Lausanne, Schweiz ER - TY - JOUR A1 - Korniienko, Yevheniia A1 - Tiedemann, Ralph A1 - Vater, Marianne A1 - Kirschbaum, Frank T1 - Ontogeny of the electric organ discharge and of the papillae of the electrocytes in the weakly electric fish Campylomormyrus rhynchophorus (Teleostei: Mormyridae) JF - The journal of comparative neurology N2 - The electric organ of the mormyrid weakly electric fish,Campylomormyrus rhynchophorus(Boulenger, 1898), undergoes changes in both the electric organ discharge (EOD) and the light and electron microscopic morphology as the fish mature from the juvenile to the adult form. Of particular interest was the appearance of papillae, surface specializations of the uninnervated anterior face of the electrocyte, which have been hypothesized to increase the duration of the EOD. In a 24.5 mm long juvenile the adult electric organ (EO) was not yet functional, and the electrocytes lacked papillae. A 40 mm long juvenile, which produced a short biphasic EOD of 1.3 ms duration, shows small papillae (average area 136 mu m(2)). In contrast, the EOD of a 79 mm long juvenile was triphasic. The large increase in duration of the EOD to 23.2 ms was accompanied by a small change in size of the papillae (average area 159 mu m(2)). Similarly, a 150 mm long adult produced a triphasic EOD of comparable duration to the younger stage (24.7 ms) but featured a prominent increase in size of the papillae (average area 402 mu m(2)). Thus, there was no linear correlation between EOD duration and papillary size. The most prominent ultrastructural change was at the level of the myofilaments, which regularly extended into the papillae, only in the oldest specimen-probably serving a supporting function. Physiological mechanisms, like gene expression levels, as demonstrated in someCampylomormyrusspecies, might be more important concerning the duration of the EOD. KW - Campylomormyrus KW - electric organ discharge KW - electrocyte ontogeny KW - electrocyte ultrastructure KW - papillae Y1 - 2020 U6 - https://doi.org/10.1002/cne.25003 SN - 0021-9967 SN - 1096-9861 VL - 529 IS - 5 SP - 1052 EP - 1065 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Korniienko, Yevheniia A1 - Nguyen, Linh A1 - Baumgartner, Stephanie A1 - Vater, Marianne A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Correction to: Intragenus F1-hybrids of African weakly electric fish (Mormyridae: Campylomormyrus tamandua male x C. compressirostris female) are fertile (vol 206, pg 571, 2020) JF - Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology Y1 - 2021 U6 - https://doi.org/10.1007/s00359-021-01513-2 SN - 0340-7594 SN - 1432-1351 VL - 207 IS - 6 SP - 773 EP - 773 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Korniienko, Yevheniia A1 - Nguyen, Linh A1 - Baumgartner, Stephanie A1 - Vater, Marianne A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Intragenus F1-hybrids of African weakly electric fish (Mormyridae: Campylomormyrus tamandua male x C. compressirostris female) are fertile JF - Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology N2 - Hybridization is widespread in fish and constitutes an important mechanism in fish speciation. There is, however, little knowledge about hybridization in mormyrids. F1-interspecies hybrids betweenCampylomormyrus tamandua male x C. compressirostris female were investigated concerning: (1) fertility; (2) survival of F2-fish and (3) new gene combinations in the F2-generation concerning the structure of the electric organ and features of the electric organ discharge. These F1-hybrids achieved sexual maturity at about 12-13.5 cm total length. A breeding group comprising six males and 13 females spawned 28 times naturally proving these F1-fish to be fertile. On average 228 eggs were spawned, the average fertilization rate was 47.8%. Eggs started to hatch 70-72 h after fertilization, average hatching rate was 95.6%. Average mortality rate during embryonic development amounted to 2.3%. Average malformation rate during the free embryonic stage was 27.7%. Exogenous feeding started on day 11. In total, we raised 353 normally developed larvae all of which died consecutively, the oldest specimen reaching an age of 5 months. During survival, the activities of the larval and adult electric organs were recorded and the structure of the adult electric organ was investigated histologically. KW - mormyridae KW - campylomormyrus KW - F1-hybrids KW - F2-hybrids KW - fertility Y1 - 2020 U6 - https://doi.org/10.1007/s00359-020-01425-7 SN - 0340-7594 SN - 1432-1351 VL - 206 IS - 4 SP - 571 EP - 585 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Kiemel, Katrin A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - DNA metabarcoding reveals impact of local recruitment, dispersal, and hydroperiod on assembly of a zooplankton metacommunity JF - Molecular ecology N2 - Understanding the environmental impact on the assembly of local communities in relation to their spatial and temporal connectivity is still a challenge in metacommunity ecology. This study aims to unravel underlying metacommunity processes and environmental factors that result in observed zooplankton communities. Unlike most metacommunity studies, we jointly examine active and dormant zooplankton communities using a DNA metabarcoding approach to overcome limitations of morphological species identification. We applied two-fragment (COI and 18S) metabarcoding to monitor communities of 24 kettle holes over a two-year period to unravel (i) spatial and temporal connectivity of the communities, (ii) environmental factors influencing local communities, and (iii) dominant underlying metacommunity processes in this system. We found a strong separation of zooplankton communities from kettle holes of different hydroperiods (degree of permanency) throughout the season, while the community composition within single kettle holes did not differ between years. Species richness was primarily dependent on pH and permanency, while species diversity (Shannon Index) was influenced by kettle hole location. Community composition was impacted by kettle hole size and surrounding field crops. Environmental processes dominated temporal and spatial processes. Sediment communities showed a different composition compared to water samples but did not differ between ephemeral and permanent kettle holes. Our results suggest that communities are mainly structured by environmental filtering based on pH, kettle hole size, surrounding field crops, and permanency. Environmental filtering based on specific conditions in individual kettle holes seems to be the dominant process in community assembly in the studied zooplankton metacommunity. KW - bulk DNA KW - dispersal KW - DNA-metabarcoding KW - environmental filtering; KW - metacommunity KW - zooplankton Y1 - 2022 U6 - https://doi.org/10.1111/mec.16627 SN - 0962-1083 SN - 1365-294X VL - 32 IS - 23 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Kiemel, Katrin A1 - Gurke, Marie A1 - Paraskevopoulou, Sofia A1 - Havenstein, Katja A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species JF - Scientific reports N2 - Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species. Y1 - 2022 U6 - https://doi.org/10.1038/s41598-022-27137-3 SN - 2045-2322 VL - 12 IS - 1 PB - Macmillan Publishers Limited CY - London ER - TY - JOUR A1 - Kiemel, Katrin A1 - Gurke, Marie A1 - Paraskevopoulou, Sofia A1 - Havenstein, Katja A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species JF - Scientific Reports N2 - Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species. Y1 - 2022 U6 - https://doi.org/10.1038/s41598-022-27137-3 SN - 2045-2322 VL - 12 PB - Springer Nature CY - London ER - TY - JOUR A1 - Kiemel, Katrin A1 - De Cahsan, Binia A1 - Paraskevopoulou, Sofia A1 - Weithoff, Guntram A1 - Tiedemann, Ralph T1 - Mitochondrial genomes of the freshwater monogonont rotifer Brachionus fernandoi and of two additional B. calyciflorus sensu stricto lineages from Germany and the USA (Rotifera, Brachionidae) JF - Mitochondrial DNA. Part B-Resources N2 - The Brachionus calyciflorus species complex was recently subdivided into four species, but genetic resources to resolve phylogenetic relationships within this complex are still lacking. We provide two complete mitochondrial (mt) genomes from B. calyciflorus sensu stricto (Germany, USA) and the mt coding sequences (cds) from a German B. fernandoi. Phylogenetic analysis placed our B. calyciflorus sensu stricto strains close to the published genomes of B. calyciflorus, forming the putative sister species to B. fernandoi. Global representatives of B. calyciflorus sensu stricto (i.e. Europe, USA, and China) are genetically closer related to each other than to B. fernandoi (average pairwise nucleotide diversity 0.079 intraspecific vs. 0.254 interspecific). KW - Mitogenome KW - cryptic species KW - Brachionus calyciflorus s KW - Brachionus KW - fernandoi KW - monogonont rotifer Y1 - 2022 U6 - https://doi.org/10.1080/23802359.2022.2060765 SN - 2380-2359 VL - 7 IS - 4 SP - 646 EP - 648 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Ketmaier, Valerio A1 - Marrone, Federico A1 - Alfonso, Giuseppe A1 - Paulus, Kirsten B. A1 - Wiemann, Annika A1 - Tiedemann, Ralph A1 - Mura, Graziella T1 - Mitochondrial DNA regionalism and historical demography in the extant populations of chirocephalus kerkyrensis (Branchiopoda: Anostraca) JF - PLoS one N2 - Background: Mediterranean temporary water bodies are important reservoirs of biodiversity and host a unique assemblage of diapausing aquatic invertebrates. These environments are currently vanishing because of increasing human pressure. Chirocephalus kerkyrensis is a fairy shrimp typical of temporary water bodies in Mediterranean plain forests and has undergone a substantial decline in number of populations in recent years due to habitat loss. We assessed patterns of genetic connectivity and phylogeographic history in the seven extant populations of the species from Albania, Corfu Is. (Greece), Southern and Central Italy. Methodology/Principal Findings: We analyzed sequence variation at two mitochondrial DNA genes (Cytochrome Oxidase I and 16s rRNA) in all the known populations of C. kerkyrensis. We used multiple phylogenetic, phylogeographic and coalescence-based approaches to assess connectivity and historical demography across the whole distribution range of the species. C. kerkyrensis is genetically subdivided into three main mitochondrial lineages; two of them are geographically localized (Corfu Is. and Central Italy) and one encompasses a wide geographic area (Albania and Southern Italy). Most of the detected genetic variation (approximate to 81%) is apportioned among the aforementioned lineages. Conclusions/Significance: Multiple analyses of mismatch distributions consistently supported both past demographic and spatial expansions with the former predating the latter; demographic expansions were consistently placed during interglacial warm phases of the Pleistocene while spatial expansions were restricted to cold periods. Coalescence methods revealed a scenario of past isolation with low levels of gene flow in line with what is already known for other co-distributed fairy shrimps and suggest drift as the prevailing force in promoting local divergence. We recommend that these evolutionary trajectories should be taken in proper consideration in any effort aimed at protecting Mediterranean temporary water bodies. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0030082 SN - 1932-6203 VL - 7 IS - 2 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Hill, Natascha A1 - Leow, Alexander A1 - Bleidorn, Christoph A1 - Groth, Detlef A1 - Tiedemann, Ralph A1 - Selbig, Joachim A1 - Hartmann, Stefanie T1 - Analysis of phylogenetic signal in protostomial intron patterns using Mutual Information JF - Theory in biosciences N2 - Many deep evolutionary divergences still remain unresolved, such as those among major taxa of the Lophotrochozoa. As alternative phylogenetic markers, the intron-exon structure of eukaryotic genomes and the patterns of absence and presence of spliceosomal introns appear to be promising. However, given the potential homoplasy of intron presence, the phylogenetic analysis of this data using standard evolutionary approaches has remained a challenge. Here, we used Mutual Information (MI) to estimate the phylogeny of Protostomia using gene structure data, and we compared these results with those obtained with Dollo Parsimony. Using full genome sequences from nine Metazoa, we identified 447 groups of orthologous sequences with 21,732 introns in 4,870 unique intron positions. We determined the shared absence and presence of introns in the corresponding sequence alignments and have made this data available in "IntronBase", a web-accessible and downloadable SQLite database. Our results obtained using Dollo Parsimony are obviously misled through systematic errors that arise from multiple intron loss events, but extensive filtering of data improved the quality of the estimated phylogenies. Mutual Information, in contrast, performs better with larger datasets, but at the same time it requires a complete data set, which is difficult to obtain for orthologs from a large number of taxa. Nevertheless, Mutual Information-based distances proved to be useful in analyzing this kind of data, also because the estimation of MI-based distances is independent of evolutionary models and therefore no pre-definitions of ancestral and derived character states are necessary. KW - Mutual Information KW - Evolution KW - Gene structure Y1 - 2013 U6 - https://doi.org/10.1007/s12064-012-0173-0 SN - 1431-7613 VL - 132 IS - 2 SP - 93 EP - 104 PB - Springer CY - New York ER - TY - JOUR A1 - Hartmann, Stefanie A1 - Helm, Conrad A1 - Nickel, Birgit A1 - Meyer, Matthias A1 - Struck, Torsten H. A1 - Tiedemann, Ralph A1 - Selbig, Joachim A1 - Bleidorn, Christoph T1 - Exploiting gene families for phylogenomic analysis of myzostomid transcriptome data JF - PLoS one N2 - Background: In trying to understand the evolutionary relationships of organisms, the current flood of sequence data offers great opportunities, but also reveals new challenges with regard to data quality, the selection of data for subsequent analysis, and the automation of steps that were once done manually for single-gene analyses. Even though genome or transcriptome data is available for representatives of most bilaterian phyla, some enigmatic taxa still have an uncertain position in the animal tree of life. This is especially true for myzostomids, a group of symbiotic ( or parasitic) protostomes that are either placed with annelids or flatworms. Methodology: Based on similarity criteria, Illumina-based transcriptome sequences of one myzostomid were compared to protein sequences of one additional myzostomid and 29 reference metazoa and clustered into gene families. These families were then used to investigate the phylogenetic position of Myzostomida using different approaches: Alignments of 989 sequence families were concatenated, and the resulting superalignment was analyzed under a Maximum Likelihood criterion. We also used all 1,878 gene trees with at least one myzostomid sequence for a supertree approach: the individual gene trees were computed and then reconciled into a species tree using gene tree parsimony. Conclusions: Superalignments require strictly orthologous genes, and both the gene selection and the widely varying amount of data available for different taxa in our dataset may cause anomalous placements and low bootstrap support. In contrast, gene tree parsimony is designed to accommodate multilocus gene families and therefore allows a much more comprehensive data set to be analyzed. Results of this supertree approach showed a well-resolved phylogeny, in which myzostomids were part of the annelid radiation, and major bilaterian taxa were found to be monophyletic. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0029843 SN - 1932-6203 VL - 7 IS - 1 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Gross, Stephanie A1 - Claus, Philip A1 - Wohlsein, Peter A1 - Kesselring, Tina A1 - Lakemeyer, Jan A1 - Reckendorf, Anja A1 - Roller, Marco A1 - Tiedemann, Ralph A1 - Siebert, Ursula T1 - Indication of lethal interactions between a solitary bottlenose dolphin (Tursiops truncatus) and harbor porpoises (Phocoena phocoena) in the German Baltic Sea JF - BMC zoology N2 - Background Aggressive interactions between bottlenose dolphins (Tursiops truncatus) and harbor porpoises (Phocoena phocoena) have been reported in different parts of the world since the late 1990s. In the Baltic Sea, harbor porpoises are the only native cetacean species, while bottlenose dolphins may appear there temporarily. In the fall of 2016, a solitary male photo-identified bottlenose dolphin stayed in the German Baltic Sea of Schleswig-Holstein for 3 months. During that time, the necropsies of the stranded harbor porpoises revealed types of trauma of varying degrees in six animals, which is unusual in this area. The purpose of this study was to determine if the appearance of the bottlenose dolphin could be linked to the trauma of the harbor porpoise carcasses. Results Pathological findings in these animals included subcutaneous, thoracic and abdominal hemorrhages, multiple, mainly bilateral, rib fractures, and one instance of lung laceration. These findings correspond with the previously reported dolphin-caused injuries in other regions. Moreover, public sighting reports showed a spatial and temporal correlation between the appearance of the dolphin and the stranding of fatally injured harbor porpoises. Conclusion Despite the fact that no attack has been witnessed in German waters to date, our findings indicate the first record of lethal interactions between a bottlenose dolphin and harbor porpoises in the German Baltic Sea. Furthermore, to our knowledge, this is the first report of porpoise aggression by a socially isolated bottlenose dolphin. KW - Cetaceans KW - Interspecific aggression KW - Porpicide KW - Blunt trauma KW - Mortality KW - Stranding Y1 - 2020 U6 - https://doi.org/10.1186/s40850-020-00061-7 SN - 2056-3132 VL - 5 IS - 1 PB - BMC CY - London ER - TY - JOUR A1 - Grobler, J. P. A1 - Hartl, G. B. A1 - Grobler, N. A1 - Kotze, A. A1 - Botha, K. A1 - Tiedemann, Ralph T1 - The genetic status of an isolated black wildebeest (Connochaetes gnou) population from the Abe Bailey Nature Reserve, South Africa : Microsatellite data on a putative past hybridization with blue wildebeest (C-taurinus) N2 - The present study aimed at assessing genetic purity of black wildebeest (Connochoetes gnou) at Abe Bailey Nature Reserve, Gauteng Province, South Africa, using a multitocus microsatellite approach. Five loci were studied in black and blue (C. taurinus) wildebeest, the latter being a closely related species and known to produce hybrids with the morphologically very similar black wildebeest. In fact, the entire national black wildebeest population of South Africa potentially contains a significant proportion of introgressed blue wildebeest genes. In our case, eight out of 39 alleles were unique to black and 22 to blue wildebeest, with nine alleles shared between pure populations of the two species in Line with their taxonomic proximity. A possible Limited past introgression of blue wildebeest genes into the Abe Bailey population, corresponding to documents on population history, was only supported by the presence of a single allele otherwise exclusively found in samples of four pure blue but not in samples of two pure black wildebeest control populations. However, an assignment test and coefficients of population divergence did not support an extended introgression of C. taurinus alleles into the C. gnou population under study. Average heterozygosity at Abe Bailey proved to be intermediate between black and blue wildebeest, the tatter species generally harbouring more genetic variation than the former owing to larger population sizes and the absence of population bottlenecks in historical times. The implications of our data are discussed with reference to the persistence of introgressed genes and the conservation of pure black wildebeest gene pools Y1 - 2005 SN - 1616-5047 ER - TY - JOUR A1 - Girndt, Antje A1 - Riesch, Rüdiger A1 - Schröder, Christiane A1 - Sehlupp, Ingo A1 - Plath, Martin A1 - Tiedemann, Ralph T1 - Multiple paternity in different populations of the sailfin molly, Poecilia latipinna JF - Animal biology N2 - Rates of multiple paternities were investigated in the sailfin molly (Poecilia latipinna), using eight microsatellite loci. Genotyping was performed for offspring and mothers in 40 broods from four allopatric populations from the south-eastern U.S.A. along a geographic stretch of 1200 km in west-east direction and approximately 200 km from north to south. No significant differences regarding rates of multiple paternities were found between populations despite sample populations stemming from ecologically divergent habitats. Even the most conservative statistical approach revealed a minimum of 70% of the broods being sired by at least two males, with an average of 1.80-2.95 putative fathers per brood. Within broods, one male typically sired far more offspring than would be expected under an assumed equal probability of all detected males siring offspring. KW - Promiscuity KW - mate choice KW - multiple paternity KW - sperm competition KW - Poeciliidae Y1 - 2012 U6 - https://doi.org/10.1163/157075611X618192 SN - 1570-7555 VL - 62 IS - 3 SP - 245 EP - 262 PB - Brill CY - Leiden ER - TY - JOUR A1 - Gessner, Jörn A1 - Arndt, Gerd-Michael A1 - Tiedemann, Ralph A1 - Bartel, Ryszard A1 - Kirschbaum, Frank T1 - Remediation measures for the Baltic sturgeon: status review and perspectives JF - Journal of applied ichthyology N2 - More than one century ago, sturgeons were prevalent species in the fish communities of all major German rivers both in the North and the Baltic seas drainages. Since then, the populations declined rapidly due to river damming, overfishing and pollution. The last sturgeon catches in the Baltic drainage system occurred during the late 1960ies. Only a few individual captures have been reported during the last 30 years with the most recent records in the Lake Ladoga ( Russia), where the last confirmed catch was recorded in 1984, and a single individual caught off Estonia in 1996. Today, sturgeons are considered missing or extinct in German waters. First attempts for remediation of the species were undertaken in the mid 1990ies. Subsequently, phylogenetic and population genetic analyses of the species were carried out using mtDNA, microsatellites, and nuclear markers ( SNPs). These genetic analyses using recent and historic material have proven the existence of two different species in the Baltic Sea in what was previously considered to represent the European Atlantic sturgeon only. In the Baltic Sea, the American Atlantic sturgeon ( A. oxyrinchus) succeeded to colonize this brackish water system during the Middle Ages. In the North Sea, the European Atlantic sturgeon ( A. sturio) is considered to be the endemic species. These results led to the separation of the remediation activities in the North Sea and the Baltic Sea tributaries. Further studies on the mechanism that lead to the extinction of A. sturio in Germany and the subsequent succession of the A. oxyrinchus mtDNA haplotype are currently been carried out. Broodstock development using the northernmost populations of A. oxyrinchus is currently under way. As a further prerequisite to re-introduce this species into the Baltic, the evaluation of the status of critical habitats for the early life stages of the American Atlantic sturgeon in the River Odra has been performed in collaboration with the Institute for Inland Fisheries of Poland. Alternative fisheries techniques, based on the data of by-catch of exotic sturgeons in the fishery, are presently developed in close cooperation with the fishery to reduce fisheries related mortality in juvenile sturgeons upon release. Monitoring of habitat utilization and migration characteristics of juvenile fish upon experimental release will have to be carried out shortly, using acoustic telemetry, with the aim to follow the fate of the released fish and to determine the best time-size-release-window for future release programmes. Y1 - 2007 U6 - https://doi.org/10.1111/j.1439-0426.2007.00925.x SN - 0175-8659 VL - 22 IS - S1 SP - 23 EP - 31 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Foerster, Verena A1 - Asrat, Asfawossen A1 - Ramsey, Christopher Bronk A1 - Brown, Erik T. A1 - Chapot, Melissa S. A1 - Deino, Alan A1 - Düsing, Walter A1 - Grove, Matthew A1 - Hahn, Annette A1 - Junginger, Annett A1 - Kaboth-Bahr, Stefanie A1 - Lane, Christine S. A1 - Opitz, Stephan A1 - Noren, Anders A1 - Roberts, Helen M. A1 - Stockhecke, Mona A1 - Tiedemann, Ralph A1 - Vidal, Celine M. A1 - Vogelsang, Ralf A1 - Cohen, Andrew S. A1 - Lamb, Henry F. A1 - Schaebitz, Frank A1 - Trauth, Martin H. T1 - Pleistocene climate variability in eastern Africa influenced hominin evolution JF - Nature geoscience N2 - Despite more than half a century of hominin fossil discoveries in eastern Africa, the regional environmental context of hominin evolution and dispersal is not well established due to the lack of continuous palaeoenvironmental records from one of the proven habitats of early human populations, particularly for the Pleistocene epoch. Here we present a 620,000-year environmental record from Chew Bahir, southern Ethiopia, which is proximal to key fossil sites. Our record documents the potential influence of different episodes of climatic variability on hominin biological and cultural transformation. The appearance of high anatomical diversity in hominin groups coincides with long-lasting and relatively stable humid conditions from similar to 620,000 to 275,000 years bp (episodes 1-6), interrupted by several abrupt and extreme hydroclimate perturbations. A pattern of pronounced climatic cyclicity transformed habitats during episodes 7-9 (similar to 275,000-60,000 years bp), a crucial phase encompassing the gradual transition from Acheulean to Middle Stone Age technologies, the emergence of Homo sapiens in eastern Africa and key human social and cultural innovations. Those accumulative innovations plus the alignment of humid pulses between northeastern Africa and the eastern Mediterranean during high-frequency climate oscillations of episodes 10-12 (similar to 60,000-10,000 years bp) could have facilitated the global dispersal of H. sapiens. KW - Evolutionary ecology KW - Limnology KW - Palaeoclimate Y1 - 2022 U6 - https://doi.org/10.1038/s41561-022-01032-y SN - 1752-0894 SN - 1752-0908 VL - 15 IS - 10 SP - 805 EP - 811 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Fiorentino, V. A1 - Manganelli, Giuseppe A1 - Giusti, Folco A1 - Tiedemann, Ralph A1 - Ketmaier, Valerino T1 - A question of time the land snail Murella muralis (Gastropoda: Pulmonata) reveals constraints on past ecological speciation JF - Molecular ecology N2 - The lively debate about speciation currently focuses on the relative importance of factors driving population differentiation. While many studies are increasingly producing results on the importance of selection, little is known about the interaction between drift and selection. Moreover, there is still little knowledge on the spatial-temporal scales at which speciation occurs, that is, arrangement of habitat patches, abruptness of habitat transitions, climate and habitat changes interacting with selective forces. To investigate these questions, we quantified variation on a fine geographical scale analysing morphological (shell) and genetic data sets coupled with environmental data in the land snail Murella muralis, endemic to the Mediterranean island of Sicily. Analysis of a fragment of the mitochondrial DNA cytochrome oxidase I gene (COI) and eight nuclear microsatellite loci showed that genetic variation is highly structured at a very fine spatial scale by local palaeogeographical events and historical population dynamics. Molecular clock estimates, calibrated here specifically for Tyrrhenian land snails, provided a framework of palaeogeographical events responsible for the observed geographical variations and migration routes. Finally, we showed for the first time well-documented lines of evidence of selection in the past, which explains divergence of land snail shell shapes. We suggest that time and palaeogeographical history acted as constraints in the progress along the ecological speciation continuum. Our study shows that testing for correlation among palaeogeography, morphology and genetic data on a fine geographical scale provides information fundamental for a detailed understanding of ecological speciation processes. KW - allopatry KW - cytochrome oxidase I gene KW - ecological speciation KW - land snails KW - microsatellites KW - Murella Y1 - 2013 U6 - https://doi.org/10.1111/mec.12107 SN - 0962-1083 SN - 1365-294X VL - 22 IS - 1 SP - 170 EP - 186 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Feulner, Philine G. D. A1 - Plath, Martin A1 - Engelmann, Jacob A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - Electrifying love : electric fish use species-specific discharge for mate recognition N2 - Mate choice is mediated by a range of sensory cues, and assortative mating based on these cues can drive reproductive isolation among diverging populations. A specific feature of mormyrid fish, the electric organ discharge (EOD), is used for electrolocation and intraspecific communication. We hypothesized that the EOD also facilitates assortative mating and ultimately promotes prezygotic reproductive isolation in African weakly electric fishes. Our behavioural experiments using live males as well as EOD playback demonstrated that female mate recognition is influenced by EOD signals and that females are attracted to EOD characteristics of conspecific males. The dual function of the EOD for both foraging and social communication (including mate recognition leading to assortative mating) underlines the importance of electric signal differentiation for the divergence of African weakly electric fishes. Thus, the EOD provides an intriguing mechanism promoting trophic divergence and reproductive isolation between two closely related Campylomormyrus species occurring in sympatry in the lower Congo rapids. Y1 - 2009 UR - http://www.journals.royalsoc.ac.uk/link.asp?id=110824 U6 - https://doi.org/10.1098/rsbl.2008.0566 SN - 1744-9561 ER - TY - JOUR A1 - Feulner, Philine g. d. A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - Eighteen microsatellite loci for endemic African weakly electric fish (Campylomormyrus, Mormyridae) and their cross species applicability among related taxa N2 - We describe isolation and characterization of the first microsatellite loci specifically developed for African weakly electric fish (Mormyridae), for the genus Campylomormyrus. Seventeen of our 18 loci are polymorphic within the Campylomormyrus numenius species complex. The polymorphic loci showed four to 15 alleles per locus, an expected heterozygosity between 0.46 and 0.94, and an observed heterozygosity between 0.31 and 1.00. Most primers also yield reproducible results in several other mormyrid species. These loci comprise a set of molecular markers for various applications, from moderately polymorphic loci suitable for population studies to highly polymorphic loci for pedigree analysis in mormyrids Y1 - 2005 ER - TY - JOUR A1 - Feulner, Philine G. D. A1 - Kirschbaum, Frank A1 - Schugardt, Christian A1 - Ketmaier, Valerio A1 - Tiedemann, Ralph T1 - Electrophysiological and molecular genetic evidence for sympatrically occuring cryptic species in African weakly electric fishes (Teleostei : Mormyridae : Campylomormyrus) N2 - For two sympatric species of African weakly electric fish, Campylomormyrus tamandua and Campylomormyrus numenius, we monitored ontogenetic differentiation in electric organ discharge (EOD) and established a molecular phylogeny, based on 2222 bp from cytochrome b, the S7 ribosomal protein gene, and four flanking regions of unlinked microsatellite loci. In C tamandua, there is one common EOD type, regardless of age and sex, whereas in C numenius we were able to identify three different male adult EOD waveform types, which emerged from a single common EOD observed in juveniles. Two of these EOD types formed well supported clades in our phylogenetic analysis. In an independent line of evidence, we were able to affirm the classification into three groups by microsatellite data. The correct assignment and the high pairwise FST values support our hypothesis that these groups are reproductively isolated. We propose that in C numenius there are cryptic species, hidden behind similar and, at least as juveniles, identical morphs. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/10557903 U6 - https://doi.org/10.1016/j.ympev.2005.09.008 SN - 1055-7903 ER - TY - JOUR A1 - Epp, Laura Saskia A1 - Stoof, Kathleen R. A1 - Trauth, Martin H. A1 - Tiedemann, Ralph T1 - Historical genetics on a sediment core from a Kenyan lake : intraspecific genotype turnover in a tropical rotifer is related to past environmental changes N2 - Using molecular genetic methods and an ancient DNA approach, we studied population and species succession of rotifers of the genus Brachionus in the Kenyan alkaline-saline crater lake Sonachi since the beginning of the 19th century as well as distribution of Brachionus haplotypes in recent and historic sediments of other lakes of the East African Rift System. The sediment core record of Lake Sonachi displays haplotypes of a distinct evolutionary lineage in all increments. Populations were dominated by a single mitochondrial haplotype for a period of 150 years, and two putatively intraspecific turnovers in dominance occurred. Both changes are concordant with major environmental perturbations documented by a profound visible change in sediment composition of the core. The first change was very abrupt and occurred after the deposition of volcanic ash at the beginning of the 19th century. The second change coincides with a major lake level lowstand during the 1940s. It was preceded by a period of successively declining lake level, in which two other haplotypes appeared in the lake. One of these putatively belongs to another species documented in historical and recent Kenyan lake sediments. The analysis of plankton population dynamics through historical time can reveal patterns of population persistence and turnover in relation to environmental changes. Y1 - 2010 UR - http://www.springerlink.com/content/100294 U6 - https://doi.org/10.1007/s10933-009-9379-7 SN - 0921-2728 ER - TY - JOUR A1 - Epp, Laura Saskia A1 - Kruse, Stefan A1 - Kath, Nadja J. A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Tiedemann, Ralph A1 - Pestryakova, Luidmila Agafyevna A1 - Herzschuh, Ulrike T1 - Temporal and spatial patterns of mitochondrial haplotype and species distributions in Siberian larches inferred from ancient environmental DNA and modeling JF - Scientific reports N2 - Changes in species’ distributions are classically projected based on their climate envelopes. For Siberian forests, which have a tremendous significance for vegetation-climate feedbacks, this implies future shifts of each of the forest-forming larch (Larix) species to the north-east. However, in addition to abiotic factors, reliable projections must assess the role of historical biogeography and biotic interactions. Here, we use sedimentary ancient DNA and individual-based modelling to investigate the distribution of larch species and mitochondrial haplotypes through space and time across the treeline ecotone on the southern Taymyr peninsula, which at the same time presents a boundary area of two larch species. We find spatial and temporal patterns, which suggest that forest density is the most influential driver determining the precise distribution of species and mitochondrial haplotypes. This suggests a strong influence of competition on the species’ range shifts. These findings imply possible climate change outcomes that are directly opposed to projections based purely on climate envelopes. Investigations of such fine-scale processes of biodiversity change through time are possible using paleoenvironmental DNA, which is available much more readily than visible fossils and can provide information at a level of resolution that is not reached in classical palaeoecology. Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-35550-w SN - 2045-2322 VL - 8 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Dominguez, Marisol A1 - Tiedemann, Ralph A1 - Reboreda, Juan C. A1 - Segura, Luciano A1 - Tittarelli, Fabian A1 - Mahler, Bettina T1 - Genetic structure reveals management units for the yellow cardinal (Gubernatrix cristata), endangered by habitat loss and illegal trapping JF - Conservation genetics KW - Genetic structure KW - Gubernatrix cristata KW - Management units KW - MtDNA KW - Microsatellites KW - Hybrids Y1 - 2017 U6 - https://doi.org/10.1007/s10592-017-0964-4 SN - 1566-0621 SN - 1572-9737 VL - 18 SP - 1131 EP - 1140 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Dolgener, Nicola A1 - Schröder, Christiane A1 - Schneeweiss, N. A1 - Tiedemann, Ralph T1 - Genetic population structure of the Fire-bellied toad Bombina bombina in an area of high population density implications for conservation JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica N2 - In this study, we report the genetic population structure of the Fire-bellied toad Bombina bombina in Brandenburg (East Germany) in the context of conservation. We analysed 298 samples originating from 11 populations in Brandenburg using mitochondrial control region sequences and six polymorphic microsatellite loci. For comparison, we included one population each from Poland and Ukraine into our analysis. Within Brandenburg, we detected a moderate variability in the mitochondrial control region (19 different haplotypes) and at microsatellite loci (9-12 alleles per locus). These polymorphisms revealed a clear population structure among toads in Brandenburg, despite a relatively high overall population density and the moderate size of single populations (100-2000 individuals). The overall genetic population structure is consistent with a postglacial colonization from South East-Europe and a subsequent population expansion. Based on genetic connectivity, we infer Management Units (MUs) as targets for conservation. Our genetic survey identified MUs, within which human infrastructure is currently preventing any genetic exchange. We also detect an unintentional translocation from South East to North West Brandenburg, presumably in the course of fish stocking activities. Provided suitable conservation measures are taken, Brandenburg should continue to harbor large populations of this critically endangered species. KW - Conservation genetics KW - Fire-bellied toad KW - Fragmentation KW - Mitochondrial DNA KW - Microsatellites KW - Translocation Y1 - 2012 U6 - https://doi.org/10.1007/s10750-012-1016-1 SN - 0018-8158 VL - 689 IS - 1 SP - 111 EP - 120 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Dolgener, Nicola A1 - Freudenberger, L. A1 - Schneeweiss, N. A1 - Ibisch, P. L. A1 - Tiedemann, Ralph T1 - Projecting current and potential future distribution of the Fire-bellied toad Bombina bombina under climate change in north-eastern Germany JF - Regional environmental change N2 - Environmental change is likely to have a strong impact on biodiversity, and many species may shift their distribution in response. In this study, we aimed at projecting the availability of suitable habitat for an endangered amphibian species, the Fire-bellied toad Bombina bombina, in Brandenburg (north-eastern Germany). We modelled a potential habitat distribution map based on (1) a database with 10,581 presence records for Bombina from the years 1990 to 2009, (2) current estimates for ecogeographical variables (EGVs) and (3) the future projection of these EGVs according to the statistical regional model, respectively, the soil and water integrated model, applying the maximum entropy approach (Maxent). By comparing current and potential future distributions, we evaluated the projected change in distribution of suitable habitats and identified the environmental variables most associated with habitat suitability that turned out to be climatic variables related to the hydrological cycle. Under the applied scenario, our results indicate increasing habitat suitability in many areas and an extended range of suitable habitats. However, even if the environmental conditions in Brandenburg may change as predicted, it is questionable whether the Fire-bellied toad will truly benefit, as dispersal abilities of amphibian species are limited and strongly influenced by anthropogenic disturbances, that is, intensive agriculture, habitat destruction and fragmentation. Furthermore, agronomic pressure is likely to increase on productive areas with fertile soils and high water retention capacities, indeed those areas suitable for B. bombina. All these changes may affect temporary pond hydrology as well as the reproductive success and breeding phenology of toads. KW - Brandenburg KW - Climate change KW - Distribution modelling KW - Endangered species KW - Fire-bellied toad KW - Maxent Y1 - 2014 U6 - https://doi.org/10.1007/s10113-013-0468-9 SN - 1436-3798 SN - 1436-378X VL - 14 IS - 3 SP - 1063 EP - 1072 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Dolgener, N. A1 - Freudenberger, L. A1 - Schluck, M. A1 - Schneeweiss, N. A1 - Ibisch, P. L. A1 - Tiedemann, Ralph T1 - Environmental niche factor analysis (ENFA) relates environmental parameters to abundance and genetic diversity in an endangered amphibian, the fire-bellied-toad (Bombina bombina) JF - Conservation genetics N2 - Increasing attempts are made to understand the factors responsible for both the demographic and genetic depletion in amphibian populations. Landscape genetics aims at a spatially explicit correlation of genetic population parameters to landscape features. Using data from the endangered fire-bellied toad Bombina bombina in Brandenburg (Northeastern Germany), we performed an environmental niche factor analysis (ENFA), relating demographic (abundance) and genetic (diversity at 17 microsatellite loci and partial sequences of the mitochondrial control region in 434 individuals from 16 populations) parameters to ecological and anthropogenic variables such as temperature, precipitation, soil wetness, water runoff, vegetation density, and road/traffic impact. We found significant correlations between road disturbance and observed heterozygosity and between soil wetness and mitochondrial diversity. As the influences of the environmental variables can differ between different indicators for genetic diversity, population size and abundance data, our ENFA-based landscape genetics approach allows us to put various aspects of long- versus short term effective population size and genetic connectivity into an ecological and spatially explicit context, enabling potentially even forecast assessment under future environmental scenarios. KW - Distribution modelling KW - ENFA KW - Genetic diversity KW - Fire-bellied toad KW - Landscape genetics KW - Road disturbance Y1 - 2014 U6 - https://doi.org/10.1007/s10592-013-0517-4 SN - 1566-0621 SN - 1572-9737 VL - 15 IS - 1 SP - 11 EP - 21 PB - Springer CY - Dordrecht ER -