@article{ReckendorfLudesWehrmeisterWohlseinetal.2018, author = {Reckendorf, Anja and Ludes-Wehrmeister, Eva and Wohlsein, Peter and Tiedemann, Ralph and Siebert, U. and Lehnert, Kristina}, title = {First record of Halocercus sp (Pseudaliidae) lungworm infections in two stranded neonatal orcas (Orcinus orca)}, series = {Parasitology}, volume = {145}, journal = {Parasitology}, number = {12}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0031-1820}, doi = {10.1017/S0031182018000586}, pages = {1553 -- 1557}, year = {2018}, abstract = {Orca (Orcinus orca) strandings are rare and post-mortem examinations on fresh individuals are scarce. Thus, little is known about their parasitological fauna, prevalence of infections, associated pathology and the impact on their health. During post-mortem examinations of two male neonatal orcas stranded in Germany and Norway, lungworm infections were found within the bronchi of both individuals. The nematodes were identified as Halocercus sp. (Pseudaliidae), which have been described in the respiratory tract of multiple odontocete species, but not yet in orcas. The life cycle and transmission pathways of some pseudaliid nematodes are incompletely understood. Lungworm infections in neonatal cetaceans are an unusual finding and thus seem to be an indicator for direct mother-to-calf transmission (transplacental or transmammary) of Halocercus sp. nematodes in orcas.}, language = {en} } @article{NagelKirschbaumHofmannetal.2018, author = {Nagel, Rebecca and Kirschbaum, Frank and Hofmann, Volker and Engelmann, Jacob and Tiedemann, Ralph}, title = {Electric pulse characteristics can enable species recognition in African weakly electric fish species}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, publisher = {Nature Publishing Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-29132-z}, pages = {1 -- 12}, year = {2018}, abstract = {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.}, language = {en} } @article{ParaskevopoulouTiedemannWeithoff2018, author = {Paraskevopoulou, Sofia and Tiedemann, Ralph and Weithoff, Guntram}, title = {Differential response to heat stress among evolutionary lineages of an aquatic invertebrate species complex}, series = {Biology letters}, volume = {14}, journal = {Biology letters}, number = {11}, publisher = {Royal Society}, address = {London}, issn = {1744-9561}, doi = {10.1098/rsbl.2018.0498}, pages = {5}, year = {2018}, abstract = {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.}, language = {en} }