TY - JOUR A1 - Wronski, Torsten A1 - Tiedemann, Ralph A1 - Apio, Ann A1 - Plath, Martin T1 - Cover, food, competitors and individual densities within bushbuck Tragelaphus scriptus female clan home ranges N2 - We examined factors predicting female densities within the common home ranges of related females ("clans") in bushbuck Tragelaphus scriptus Pallas, 1776. In this species, each female forms an individual home range, but the home ranges of matrilineal clan members strongly overlap. We found female densities to increase in areas with high canopy cover. Moreover, individual home range sizes tended to decrease with increasing cover. Food plant availability and intruder pressure by two heterospecific competitors did not significantly affect female densities. Apparently, canopy cover is the major limited resource in this species. A possible explanation is that both adult bushbuck and - even more markedly - fawns hide from predators in dense vegetation, in particular in thicket clumps and coalescences. The study shows an effect of habitat properties (eg sufficient canopy cover) on a within-population level in bushbuck, where female densities differ even among proximate clan areas Y1 - 2006 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 - 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 - Regenberg, Marcus A1 - Steph, Silke A1 - Nuernberg, Dirk A1 - Tiedemann, Ralph A1 - Garbe-Schoenberg, Dieter T1 - Calibrating Mg/Ca ratios of multiple planktonic foraminiferal species with delta O-18-calcification temperatures : paleothermometry for the upper water column N2 - In order to consistently approximate the thermal vertical structure of past upper water columns, Mg/Ca ratios of eight planktonic foraminiferal species with different preferential calcification depths selected from 76 tropical Atlantic and Caribbean sediment-surface samples were calibrated with delta O-18-derived calcification temperatures with an overall range of approximate to 8-28 degrees C. Extending the broad number of species-specific calibrations, which agree well especially with our shallow-dweller calibrations, this study presents new bulk calcite Mg/Ca vs. calcification temperature relationships for shallow-dwelling Globigerinoides ruber pink, thermocline-dwelling Globorotalia menardii, and deep-dwelling Globorotalia truncatulinoides dextral and Globorotalia crassaformis not separately calibrated before. The species-specific temperature sensitivities are relatively similar (approximate to 7- 11% increase in Mg/Ca per 1 degrees C), yet y-axis intercepts vary from 0.23-0.65 for the shallow and thermocline dwellers to 0.83-1.32 for the deep dwellers. Based on these differences, we established a 'warm water' calibration for temperatures > 19 degrees C (Mg/Ca=0.29.exp(0.101.T): r=0.90; shallow and thermocline dwellers) and a 'cold water' calibration for temperatures < 15 degrees C (Mg/Ca=0.84.exp(0.083.T); r=0.85; deep dwellers). These calibrations are offset by approximate to 8 degrees C. This maybe significant for paleotemperature reconstructions, which are afflicted with the problem that similar Mg/Ca offsets are probably characteristic of extinct species used to calculate past temperatures. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/0012821X U6 - https://doi.org/10.1016/j.epsl.2008.12.019 SN - 0012-821X ER - TY - JOUR A1 - Plath, Martin A1 - Kromuszczynski, Katja A1 - Tiedemann, Ralph T1 - Audience effect alters male but not female mating preferences N2 - Males often face strong mating competition by neighboring males in their social environment. A recent study by Plath et al. (Anim Behav 75:21-29, 2008a) has demonstrated that the visual presence of a male competitor (i.e., an audience male) affects the expression of male mating preferences in a poeciliid fish (Poecilia mexicana) with a weaker expression of mating preferences when an audience male observed the focal male. This may be a tactic to reduce sperm competition, since surrounding males likely share intrinsic preferences for female traits or copy mate choice decisions. Here, we examined the hypothesis that a same-sex audience would affect female mate preferences less than male mating preferences. Our hypothesis was based on the assumptions that (1) competition for mates in a fashion that would be comparable in strength to sperm competition or overt male-male aggression is absent among Poecilia females, and (2) P. mexicana females typically form female-biased shoals, such that almost any female mate choice in nature occurs in front of a female audience. Poecilia females (P. mexicana, surface and cave form, and the closely related gynogenetic Poecilia formosa) were given a choice between a large and a small male, and the tests were repeated while a conspecific, a heterospecific, or no audience female (control) was presented. Females spent more time in the neutral zone and, thus, less time near the males during the second part of a trial when an audience was presented, but-consistent with predictions-females showed only slightly weaker expression of mate preferences during the second part of the tests. This decline was not specific to the treatment involving an audience and was significantly weaker than the effect seen in the male sex. Y1 - 2009 UR - http://www.springerlink.com/content/100464 U6 - https://doi.org/10.1007/s00265-008-0672-7 SN - 0340-5443 ER - TY - JOUR A1 - Bleidorn, Christoph A1 - Hill, Natascha A1 - Erséus, Christer A1 - Tiedemann, Ralph T1 - On the role of character loss in orbiniid phylogeny (Annelida) : molecules vs. morphology N2 - Orbiniid phylogeny is matter of debate and incongruence between hypothesis based on molecules and morphology has been repeatedly reported. Moreover, the phylogenetic position of the "oligochaetoid polychaetes" of the taxon Questa varies between morphological and molecular cladistic analyses. Here, we present a nearly complete mitochondrial genome of Questa ersei. The mitochondrial gene order is roughly identical to known orbiniid taxa. Several translocations of tRNAs are unique to Orbiniidae and Questa when compared to other annelid mitochondrial genomes. Additionally, we assembled sequence data of six genes (18S, 16S, cox1, cox3, nad1, nad4) for a representative orbiniid taxon sampling and analysed all data in concatenation using Maximum Likelihood and Bayesian inference. For comparison with morphology we compiled a morphological data matrix for all taxa included in our molecular analyses. Our results strongly support a close relationship of Questa with orbiniids (sequence data, gene order, an 18 bp indel, morphology), and a position nested within orbiniids is recovered in our sequence based analyses. We demonstrate remarkable incongruence of most included morphological characters with the recovered best ML tree and suppose that repeated independent character loss might be an explanation. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/10557903 U6 - https://doi.org/10.1016/j.ympev.2009.03.022 SN - 1055-7903 ER - TY - JOUR A1 - Bleidorn, Christoph A1 - Lanterbecq, Deborah A1 - Eeckhaut, Igor A1 - Tiedemann, Ralph T1 - A PCR survey of Hox genes in the myzostomid Myzostoma cirriferum N2 - Using degenerate primers, we were able to identify seven Hox genes for the myzostomid Myzostoma cirriferum. The recovered fragments belong to anterior class (Mci_lab, Mci_pb), central class (Mci_Dfd, Mci_Lox5, Mci_Antp, Mci_Lox4), and posterior class (Mci_Post2) paralog groups. Orthology assignment was verified by phylogenetic analyses and presence of diagnostic regions in the homeodomain as well as flanking regions. The presence of Lox5, Lox4, and Post2 supports the inclusion of Myzostomida within Lophotrochozoa. We found signature residues within flanking regions of Lox5, which are also found in annelids, but not in Platyhelminthes. As such the available Hox genes data of myzostomids support an annelid relationship. Y1 - 2009 UR - http://www.springerlink.com/content/100526 U6 - https://doi.org/10.1007/s00427-009-0282-z SN - 0949-944X ER - TY - JOUR A1 - Sharma, Reeta A1 - Stuckas, Heiko A1 - Bhaskar, Ranjana A1 - Rajput, Sandeep A1 - Khan, Imran A1 - Goyal, Surendra Prakash A1 - Tiedemann, Ralph T1 - mtDNA indicates profound population structure in Indian tiger (Panthera tigris tigris) N2 - We analyzed mtDNA polymorphisms (parts of control region, ND5, ND2, Cytb, 12S, together 902 bp) in 59 scat and 18 tissue samples from 13 Indian populations of the critically endangered Indian tiger (Panthera tigris tigris), along with zoo animals as reference. Northern tiger populations exhibit two unique haplotypes suggesting genetic isolation. Western populations from Sariska (extinct in 2004) and Ranthambore are genetically similar, such that Ranthambore could serve as a source for reintroduction in Sariska. Zoo populations maintain mitochondrial lineages that are rare or absent in the wild. Y1 - 2009 UR - http://www.springerlink.com/content/105709 U6 - https://doi.org/10.1007/s10592-008-9568-3 SN - 1566-0621 ER - TY - JOUR A1 - Stuckas, Heiko A1 - Stoof, Kathleen A1 - Quesada, Humberto A1 - Tiedemann, Ralph T1 - Evolutionary implications of discordant clines across the Baltic Mytilus hybrid zone (Mytilus edulis and Mytilus trossulus) N2 - It is well established that reproductive isolation often arises from genome incompatibilities and that genes encoding reproductive traits are less prone to introgression. Hybrid zones of Mytilus trossulus and Mytilus edulis provide an intriguing model to assess reproductive isolation. Although gene flow is restricted in North America, introgression is pervasive in the Baltic. This study aimed at analyzing the shape of multilocus clines across the Baltic contact zone between M. edulis and M. trossulus to infer mechanisms of restriction to gene flow. We use maximum likelihood methods to construct the best fitting individual clines for five markers located on biparentally inherited autosomes and paternally and maternally inherited mitochondrial DNA (mtDNA). Strong cline shape differences among markers suggest that reproductive isolation arising from genome-wide incompatibilities is weak, and that these discrepancies possibly result from genetic drift, hybrid zone movement or marker-specific selection. However, the finding of a common cline center for M7 lysin (involved in fertilization) and paternally transmitted mtDNA (causing nuclear-mitochondrial incompatibilities in hybrids) suggest that these loci may play a role in incomplete reproductive isolation. Y1 - 2009 UR - http://www.nature.com/hdy/archive/index.html U6 - https://doi.org/10.1038/Hdy.2009.37 SN - 0018-067X 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 -