Deutsches Meeresmuseum

Katharinenberg, Germany

Deutsches Meeresmuseum

Katharinenberg, Germany
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Brager Z.,University of Pécs | Moritz T.,Deutsches Meeresmuseum | Moritz T.,Friedrich - Schiller University of Jena
Vertebrate Zoology | Year: 2016

Regular body scales of 80 species, belonging to 50 families and 16 orders of marine teleost fishes common in the Mediterranean Sea are described using morphological and morphometric characters. The morphological descriptions are based on the scale's type, shape, features of the anterior, posterior and lateral fields. Further characteristics of the focus, circuli, radii and spines or cteni, if present, are given. Morphometric indices are calculated for scales from the anterior dorsal flank area of each species. As scale shape varies along the body of a given specimen, respective images are provided generally from ten body areas. The current atlas also provides information that complements the characterization of certain taxa. In addition, it is to constitute a valuable instrument for species identification of scales collected from fossiliferous layers, from archaeological sites or from a variety of feeding remains of piscivorous marine predators. © Senckenberg Gesellschaft für Naturforschung, 2016.

Moritz T.,Deutsches Meeresmuseum | Moritz T.,Friedrich - Schiller University of Jena | Neumann D.,Zoologische Staatssammlung Munich
Cybium | Year: 2017

A new Labeo species was discovered during surveys conducted on the Nile basin in Sudan between 2006 and 2016. It is described herein as Labeo latebra sp. nov. It differs from all other Labeo species of the Nile basin by having only 12, rarely 13, scales around the caudal peduncle (instead of 16 or more), and from all Labeo species occurring in the Nile River except L. meroensis by having only 4.5, rarely 5.5, scales between lateral line and dorsal fin base (vs. 6.5-7.5 in L.forskalii and L. coubie, 6.5-8.5 in L. horie, and 8.5-9.5 in L. niloticus). It can be distinguished from L. meroensis by 34-37 scales in lateral line (vs. 39-41 in L. meroensis). Compared to other species of the genus in the Main Nile, the rostral flap is largely fused with the lip and has only a small free part. Labeo latebra sp. nov. is a rather compact and cylindrical Labeo species with a weakly swollen snout while all other Nilotic Labeo species have a clearly elongate appearance and a laterally compressed body. © SFI.

PubMed | Tethys Research Institute, Szent Istvan University, Aristotle University of Thessaloniki, Deutsches Meeresmuseum and 2 more.
Type: Journal Article | Journal: Journal of fish biology | Year: 2016

Landmark-based geometric morphometric analysis revealed differences in scale shape between European sardine Sardina pilchardus and round sardinella Sardinella aurita as well as among the local populations of each species. Fish scale measurements from four different areas in the central and eastern Mediterranean Sea showed that the mean scale shape of the two species using landmark data could be differentiated with high certainty. Populations of S. aurita from the central and eastern Mediterranean Sea could be separated reliably (P < 0001) with an average discrimination rate of 91%, whereas the average discrimination of the S. pilchardus populations was lower (80%), albeit still high.

PubMed | University of Veterinary Medicine Hannover, University of Gdansk, Deutsches Meeresmuseum, Newcastle University and 5 more.
Type: Journal Article | Journal: PloS one | Year: 2016

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.

Day J.J.,University College London | Peart C.R.,University College London | Peart C.R.,Natural History Museum in London | Brown K.J.,University College London | And 4 more authors.
Systematic Biology | Year: 2013

Despite African rivers containing high species diversity, continental-scale studies investigating the mechanisms generating biological diversity of African riverine faunas are limited compared with lacustrine systems. To investigate the build-up of diversity in a tropical aquatic continental radiation, we test different models of lineage diversification and reconstruct the biogeographic history in a species-rich siluriform genus, Synodontis (~130 species), with a broad distribution across all major tropical African drainage basins. The resulting robust species-level phylogeny (~60% complete, based on a multigene data set) exhibits a near constant rate of lineage accumulation throughout the mid-Cenozoic to recent, irrespective of missing species and despite the changing environmental conditions that were prevalent during this time period. This pattern contrasts with the findings for species-level diversification of large clades that commonly show an early burst of cladogenesis followed by declining rates through time. The identification of distinct biogeographic clades demonstrates a correlation between river hydrology and cladogenesis, although there is evidence of recent repeat dispersal into the southern range of the focal group. We conclude that diverse freshwater fish radiations with tropical continental distributions represent important organisms to test hypotheses of diversification and investigate the effects of palaeo-landscapes and climates on present day biodiversity. © 2013 The Author(s).

Field studies on the electric organ discharges (EODs) of Mormyrus species are rare, likely due to their biology hindering live capture in large numbers. Here the EODs of four Nilo-Sahelo-Sudanic species, Mormyrus caschive Linnaeus, 1758, M. kannume Forsskål, 1775, M. hasselquistii Valenciennes, 1847 and M. rume Valenciennes, 1847, are compared and discussed. Their discharges are largely equal to each other, mainly showing differences in length and peak of Fourier transformation with less pronounced differences in the relative amplitude of phases within an EOD. The discharge properties allow species discrimination, at least within eco-regions, and thus likely play a role in species recognition. © SFI.

Moritz T.,Deutsches Meeresmuseum | Moritz T.,Friedrich - Schiller University of Jena | Schliewen U.K.,SNSB Bavarian State Collection of Zoology ZSM
Zootaxa | Year: 2016

Two new species of Bathyaethiops (Teleostei: Characiformes: Alestidae) are described. Bathyaethiops baka n. Sp. is a dwarf species with the largest known specimen being only 24.4 mm SL. The species is characterized by an incomplete squamation and a large humeral spot. Bathyaethiops baka n. Sp. is known so far only from the Ngoko River of Southeastern Cameroon, a tributary of the Sangha River in the northern Congo basin. The second species, Bathyaethiops flammeus n. Sp., shows a diagnostic spot in front of the dorsal-fin base, which is devoid of melanophores and bright red in life. The species is described from the Bakéré River at Yambula-Bakéré, a locality north-west of Kisangani in the Central Congo basin. Other records of Bathyaethiops flammeus n. Sp.from the Tshuapa respectively Ruki River at Boende and Eala, Central Congo basin, suggests a wider geographic distribution. A key to all species of Bathyaethiops is provided. Copyright © 2016 Magnolia Press.

Stemmer K.,Ruhr University Bochum | Burghardt I.,Leibniz Center for Tropical Marine Ecology | Mayer C.,Ruhr University Bochum | Reinicke G.B.,Deutsches Meeresmuseum | And 3 more authors.
Organisms Diversity and Evolution | Year: 2013

Studies on the biodiversity and evolution of octocorals are hindered by the incomplete knowledge of their taxonomy, which is due to few reliable morphological characters. Therefore, assessment of true species diversity within abundant and ecologically important families such as Xeniidae is difficult. Mitochondrial genes provide a reliable solution to this problem for a wide range of taxa. However, low mutation rates of the mitochondrial DNA in octocorals result in insufficient variability for species discrimination. We compared the variation of a fragment of the Signal Recognition Particle 54 gene (SRP54, proposed for octocorals) and the mitochondrial ND6/ND3 marker among members of the xeniid genera Ovabunda, Xenia, Heteroxenia and Bayerxenia. The mean uncorrected pairwise sequence divergence was 39 % for SRP54 compared to 2 % for ND6/ND3. Morphological assignments were not always supported by genetics: Species diversity was underestimated (one case) or overestimated, probably reflecting intraspecific polymorphisms or hinting at recent speciations. ND6/ND3 is informative for some species-level assignments, whereas SRP54 shows the variability needed for species delimitations within this understudied taxon. Our results on both genes show their potential for evolutionary and biodiversity studies in Xeniidae. © 2012 Gesellschaft für Biologische Systematik.

Bender A.,University of Tübingen | Moritz T.,Deutsches Meeresmuseum
Zoosystematics and Evolution | Year: 2013

The adipose fin is a structure with questionable function, for a long time even regarded as a rudimentary element without any function. A comparative study of adipose fin development revealed two different modes: a salmoniform-type where the adipose fin develops directly from the larval fin fold simultaneously with the other median fins. And a characiform-type where the adipose fin develops anew after the reduction of the larval fin fold. Compared to the first mode the latter starts late in ontogeny, when all other median fins already have their shape, fin rays and colouration. The characiform-type of adipose fin development contradicts the view that this structure is just a larval fin fold remainder. It also disputes the hypothesis of the adipose fin as a structure without any function. Such a hypothesis cannot explain a systematically widely distributed structure which even exhibits different modes of ontogenetic development in different taxa.© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

For the understanding and interpretation of molecular phylogenies it is important to understand and critically question the underlying gene trees, because a gene tree merely depicts the history of a gene or DNA segment, but not necessarily the history of the respective species tree. An approximation to the species tree can be reached only by a combined reconstruction of several independent gene trees. Based on three examples the use and pitfalls of molecular methods for ornithological taxonomy will be illustrated. Within the birds of prey (Accipitriformes) the analysis of seven independent genes and intron sequences yielded surprising results: The genus Aquila is not monophyletic in its traditional delimitation but instead demands the inclusion of Bonelli's Eagle, Hawk-Eagle and eight further genera. The genus Accipiter also is not monophyletic but divides into four distinct species groups. However, a revision of the genus appears difficult, because the Harriers are closely related to one of the Accipiter sub-groups. The currently accepted phylogeny of gulls (Laridae), rearranged on the basis of premature molecular data, seems not plausible anymore. After increasing the amount of sequenced data the genus Larus appears monophyletic again, hence the splitting into several genera should be withdrawn. The oldest, basal groups of gulls, still separated from the genus Larus, includes such diverse species as Little Gull and Ross's Gull, Kittiwake as well as Ivory Gull and Sabine's Gull. Within the reed warblers (Acrocephalidae) the analysis of four sequenced genes showed that the four traditional genera are not monophyletic. The Acrocephalus Warblers form three distinct groups of the same ancestry, while the Thick-billed Warbler is excluded from the genus. The Hippolais and Chloropeta Warblers also present no reciprocal monophyletic groups, leading to a revision of the respective genera Hippolais, Iduna and Calamonastides. The examples given illustrate how difficult it is to interpret the wide array of recently published molecular studies. This is especially challenging for all ornithologists who are indeed interested in phylogeny, but are not familiar with the vast variety of molecular methods. The common reader of a publication cannot assess the plausibility of the presented phylogeny. Therefore it is always advisable to question whether the trees are in concordance with morphological, acoustical and biogeographical features of the respective group.

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