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Puniamoorthy N.,University of Zürich | Puniamoorthy N.,National University of Singapore | Kotrba M.,Bavarian State Collection of Zoology | Meier R.,National University of Singapore
BMC Evolutionary Biology | Year: 2010

Background. The species-specificity of male genitalia has been well documented in many insect groups and sexual selection has been proposed as the evolutionary force driving the often rapid, morphological divergence. The internal female genitalia, in sharp contrast, remain poorly studied. Here, we present the first comparative study of the internal reproductive system of Sepsidae. We test the species-specificity of the female genitalia by comparing recently diverged sister taxa. We also compare the rate of change in female morphological characters with the rate of fast-evolving, molecular and behavioral characters. Results. We describe the ectodermal parts of the female reproductive tract for 41 species representing 21 of the 37 described genera and define 19 morphological characters with discontinuous variation found in eight structures that are part of the reproductive tract. Using a well-resolved molecular phylogeny based on 10 genes, we reconstruct the evolution of these characters across the family [120 steps; Consistency Index (CI): 0.41]. Two structures, in particular, evolve faster than the rest. The first is the ventral receptacle, which is a secondary sperm storage organ. It accounts for more than half of all the evolutionary changes observed (7 characters; 61 steps; CI: 0.46). It is morphologically diverse across genera, can be bi-lobed or multi-chambered (up to 80 chambers), and is strongly sclerotized in one clade. The second structure is the dorsal sclerite, which is present in all sepsids except Orygma luctuosum and Ortalischema albitarse. It is associated with the opening of the spermathecal ducts and is often distinct even among sister species (4 characters; 16 steps; CI: 0.56). Conclusions. We find the internal female genitalia are diverse in Sepsidae and diagnostic for all species. In particular, fast-evolving structures like the ventral receptacle and dorsal sclerite are likely involved in post-copulatory sexual selection. In comparison to behavioral and molecular data, the female structures are evolving 2/3 as fast as the non-constant third positions of the COI barcoding gene. They display less convergent evolution in characters (CI = 0.54) than the third positions or sepsid mating behavior (CICOI= 0.36; CIBEHAV= 0.45). © 2010 Puniamoorthy et al; licensee BioMed Central Ltd.

Lerosey-Aubril R.,University Claude Bernard Lyon 1 | Lerosey-Aubril R.,Senckenberg Institute | Meyer R.,Bavarian State Collection of Zoology
Biological Reviews | Year: 2013

The cuticle of crustaceans bears numerous organs, of which the functions of many are unknown. One of these, the sensory dorsal organ (SDO), is present in a wide diversity of taxa. Here we critically review the variability, ultrastructure, distribution, and possible function of this enigmatic cuticular organ. Previous data are complemented by new observations on larvae and adults of various malacostracans. The SDO is composed of four sensors arranged as the corners of a square, the centre of which is occupied by a gland. Pores or pegs surrounding this central complex may also form part of the organ. The arrangement and the external aspect of the five main elements varies greatly, but this apparently has little impact on their ultrastructural organisation. The sensors and the gland are associated with a particularly thin cuticle. Each sensor contains four outer dendritic segments and the central gland is made of a single large cell. It is not yet known what this large cell secretes. The SDO is innervated from the tritocerebrum and therefore belongs to the third cephalic segment. A similar organ, here called the posterior SDO, has been repeatedly observed more posteriorly on the carapace. It resembles the SDO but has a greater number of sensors (usually six, but up to ten) apparently associated with only two outer dendritic segments. The SDO and the posterior SDO are known in the Eumalacostraca, the Hoplocarida, and the Phyllocarida. Some branchiopods also possess a 'dorsal organ' resembling both the SDO and the ion-transporting organ more typical of this group. This may indicate a common origin for these two functionally distinct groups of organs. New observations on the posterior SDO support the hypothesis that the SDO and the posterior SDO are homologous to the lattice organ complexes of thecostracans. However, the relationship between the SDO and the dorsal cephalic hump of calanoid copepods remains unclear. No correlation can be demonstrated between the presence of a SDO and a particular ecological or biological trait. In fossils, the most convincing examples of SDO-like organs are found in some Late Cambrian arthropods from the Alum Shale of southern Sweden. They suggest that related organs might have been present in non-crustacean Cambrian arthropods. The distribution of the SDO and posterior SDO in extant and fossil crustaceans strongly suggests that these organs originated early in the history of the group, and are crucial to the functioning of these organisms. However, except for knowing that the sensors are chemoreceptors and that in a given organ a functional relationship probably exists between them and the gland, little is known about this function. The description of a SDO in freshwater carideans, which can be easily reared in a laboratory, opens the way for behavioural and physiological experiments to be undertaken that could prove crucial for the determination of this function. © 2012 Cambridge Philosophical Society.

News Article | March 17, 2016
Site: phys.org

A collaborative research study carried out by the Technical University Munich (TUM) and Bavarian State Collection of Zoology (ZSM) confirms the species loss of past decades and the modest effectiveness of nature and species conservation. The study is based on one of the longest observation series ever carried out. Species lists and butterfly collections from 1840 until today were evaluated. All of the data were provided by lepidopterologists, i.e. butterfly researchers, from areas around the city of Regensburg in Bavaria. The southern slopes along the Danube there mainly consist of rare oligotrophic grasslands and, accordingly, oligotrophic biotopes for butterflies and other insects. Around 45 hectares of land there have been designated as a conservation area since 1992. The institutes involved in the study included beside TUM and ZSM also the Senckenberg German Entomological Institute, and Nicolaus Copernicus University Torun, Poland. The results of the collaborative study were published in the American journal Conservation Biology. "The observations carried out over a period of 200 years confirm the general trend of a decline in habitat specialist species despite the fact that these species are the target of nature conservation measures," explains Dr. Jan Christian Habel from TUM's Terrestrial Ecology Research Group. For example whereas 117 butterfly species and diurnal moths were recorded between 1840 and 1849, only 71 species were recorded between 2010 and 2013. Moreover, the composition of the butterfly species also changed. While the region was populated by a diverse butterfly community during the past, it is now dominated by a few habitat generalists. Many habitat specialists, which require certain larval host plants and habitat structures to survive, have disappeared. According to the study, high emissions of reactive nitrogen is one of the reasons of this species decline. Reactive nitrogen is generated, for example, by the combustion of the fossil fuels wood and peat, industrial incineration processes, the cultivation of legumes, and the increasingly intensive agriculture of recent decades. Nitrogen alters the nutrient composition of plants by the airborne route and overfertilizes the very sensitive type of vegetation found in this region. But the flora and fauna there are adapted to a low-nutrient environment. The high nitrogen supply promotes the growth of plants like the dandelion, thistles, and sorrel, which oust the typical flora and, hence also, larval host plants. "These changes in the environment have a very serious impact on the habitat specialists," says the biogeographer from TUM. "Most conservation areas are very small and isolated and sparsely distributed in the landscape," says Habel - "Moreover, atmospheric nitrogen does not respect the boundaries of the protected areas." According to the study, despite climate warming, thermophilic species, which like warm and dry conditions, are also in decline. This may seem surprising to non-experts." The vegetation is growing faster due to the nitrogen inputs. This creates more shade close to the ground, which is too much shade for heat-loving butterflies," explains Habel. Because the observations used for the study were recorded using very different methods by the scientists involved, they could only be used as records of the presence and disappearance of the recorded species. It was not possible to calculate species abundances and population densities and development in relation to abundance. "The question that emerges here is whether the established network of fauna-flora habitat conservation areas will enable us to achieve effective nature conservation in the long term," adds Dr. Habel. "The answer is clearly no." Explore further: How to save Europe's most threatened butterflies

Schwarzer J.,Zoologisches Forschungsmuseum Alexander Koenig | Misof B.,Zoologisches Forschungsmuseum Alexander Koenig | Schliewen U.K.,Bavarian State Collection of Zoology
Journal of Evolutionary Biology | Year: 2012

Hybridization in animals is a much more common phenomenon as previously thought and may have profound implications for speciation research. The cichlid genus Steatocranus (Teleostei: Cichlidae), a close relative to members of the East African cichlid radiations, radiated under riverine conditions in the lower Congo rapids and produced a small species flock. Previous phylogenetic analyses suggested that hybridization occurred and contributed to speciation in this genus. A re-analysis of an already published 2000 loci-AFLP data set explicitly testing for patterns of ancient gene flow provided strong evidence for a highly reticulate phylogenetic history of the genus. We provide, to our knowledge, the first example of a complex reticulate network in vertebrates, including multiple closely related species connected through ancient as well as recent gene flow. In this context, the limited validity of strictly bifurcating tree hypotheses as a phylogenetic basis for hypothesis testing in evolutionary biology is discussed. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

Schwarzer J.,Bavarian State Collection of Zoology | Misof B.,Zoologisches Forschungsmuseum Alexander Koenig | Ifuta S.N.,ISP GOMBE | Schliewen U.K.,Bavarian State Collection of Zoology
PLoS ONE | Year: 2011

Most freshwater diversity is arguably located in networks of rivers and streams, but, in contrast to lacustrine systems riverine radiations, are largely understudied. The extensive rapids of the lower Congo River is one of the few river stretches inhabited by a locally endemic cichlid species flock as well as several species pairs, for which we provide evidence that they have radiated in situ. We use more that 2,000 AFLP markers as well as multilocus sequence datasets to reconstruct their origin, phylogenetic history, as well as the timing of colonization and speciation of two Lower Congo cichlid genera, Steatocranus and Nanochromis. Based on a representative taxon sampling and well resolved phylogenetic hypotheses we demonstrate that a high level of riverine diversity originated in the lower Congo within about 5 mya, which is concordant with age estimates for the hydrological origin of the modern lower Congo River. A spatial genetic structure is present in all widely distributed lineages corresponding to a trisection of the lower Congo River into major biogeographic areas, each with locally endemic species assemblages. With the present study, we provide a phylogenetic framework for a complex system that may serve as a link between African riverine cichlid diversity and the megadiverse cichlid radiations of the East African lakes. Beyond this we give for the first time a biologically estimated age for the origin of the lower Congo River rapids, one of the most extreme freshwater habitats on earth. © 2011 Schwarzer et al.

Schwabe E.,Bavarian State Collection of Zoology
Spixiana | Year: 2010

The aims of the present paper are to summarize and offer a standard set of terminology used to describe morphological and partly anatomical (e. g. the radula) characters of Polyplacophora. To make the understanding of some previously misused terms easier, the identification and description of relevant parts of the animal are illustrated and discussed in context of additional literature.

Stoger I.,Bavarian State Collection of Zoology | Schrodl M.,Bavarian State Collection of Zoology | Schrodl M.,GeoBio Center
Molecular Phylogenetics and Evolution | Year: 2013

The origin of molluscs among lophotrochozoan metazoans is unresolved and interclass relationships are contradictory between morphology-based, multi-locus, and recent phylogenomic analyses. Within the "Deep Metazoan Phylogeny" framework, all available molluscan mitochondrial genomes were compiled, covering 6 of 8 classes. Genomes were reannotated, and 13 protein coding genes (PCGs) were analyzed in various taxon settings, under multiple masking and coding regimes. Maximum Likelihood based methods were used for phylogenetic reconstructions. In all cases, molluscs result mixed up with lophotrochozoan outgroups, and most molluscan classes with more than single representatives available are non-monophyletic. We discuss systematic errors such as long branch attraction to cause aberrant, basal positions of fast evolving ingroups such as scaphopods, patellogastropods and, in particular, the gastropod subgroup Heterobranchia. Mitochondrial sequences analyzed either as amino acids or nucleotides may perform well in some (Cephalopoda) but not in other palaeozoic molluscan groups; they are not suitable to reconstruct deep (Cambrian) molluscan evolution.Supposedly "rare" mitochondrial genome level features have long been promoted as phylogenetically informative. In our newly annotated data set, features such as genome size, transcription on one or both strands, and certain coupled pairs of PCGs show a homoplastic, but obviously non-random distribution. Apparently congruent (but not unambiguous) signal for non-trivial subclades, e.g. for a clade composed of pteriomorph and heterodont bivalves, needs confirmation from a more comprehensive bivalve sampling. We found that larger clusters not only of PCGs but also of rRNAs and even tRNAs can bear local phylogenetic signal; adding trnG-trnE to the end of the ancestral cluster trnM-trnC-trnY-trnW-trnQ might be synapomorphic for Mollusca. Mitochondrial gene arrangement and other genome level features explored and reviewed herein thus failed as golden bullets, but are promising as additional characters or evidence supporting deep molluscan clades revealed by other data sets. A representative and dense sampling of molluscan subgroups may contribute to resolve contentious interclass relationships in the future, and is vital for exploring the evolution of especially diverse mitochondrial genomes in molluscs. © 2012 Elsevier Inc.

Geiselbrecht H.,Bavarian State Collection of Zoology | Geiselbrecht H.,Ludwig Maximilians University of Munich | Melzer R.R.,Bavarian State Collection of Zoology
Arthropod Structure and Development | Year: 2013

The mandibles of decapod zoea-I larvae are robustly built masticating mouthparts equipped with several processes and spines. Superficial examination of these sturdy, inflexible structures can suggest that they are lacking sensory receptors. However, detailed TEM analysis of their ultrastructure revealed up to 11 sensillar cell clusters on the gnathal edges of the mandibles of the zoea-I in Palaemon elegans Rathke, 1837. Based on ultrastructural criteria we distinguish 7 types of sensilla: mechanoreceptors, chemoreceptors and mechano- and chemoreceptors. One sensory unit located at the base of the 'lacinia mobilis' exhibits the typical features of a crustacean mechanosensitive sensillum with an external seta and corresponding ultrastructure. Another unit shows features indicating bimodal contact chemosensitivity. A third one is similar to known olfactory chemoreceptors.Using the concept of modality-specific structures we analyse the structure and functional morphology of each sensillum, and give a comprehensive overview of the sensory abilities of zoea mandibles. We take a closer look at the ultrastructure of the 'lacinia mobilis', providing further features to trace its evolutionary history in Decapoda, and thus contributing to a better understanding of malacostracan phylogeny. © 2012 Elsevier Ltd.

Dunz A.R.,Bavarian State Collection of Zoology | Schliewen U.K.,Bavarian State Collection of Zoology
Molecular Phylogenetics and Evolution | Year: 2013

•Phylogenetic analyses of a comprehensive multilocus dataset comprising almost all haplotilapiine cichlid tribes.•Enlarged mtDNA (ND2) dataset comprising about 60% of all described Pseudocrenilabrinae genera.•A novel classification of "Tilapia" and related lineages defined by putative molecular synapomorphies. African cichlids formerly referred to as ". Tilapia" represent a paraphyletic species assemblage belonging to the so called haplotilapiine lineage which gave rise to the spectacular East African cichlid radiations (EARs) as well as to globally important aquaculture species. We present a comprehensive molecular phylogeny of representative haplotilapiine cichlids, combining in one data set four mitochondrial and five nuclear loci for 76 species, and compare it with phylogenetic information of a second data set of 378 mitochondrial ND2 haplotypes representing almost all important ". Tilapia" or Tilapia-related lineages as well as most EAR lineages. The monophyly of haplotilapiines is supported, as is the nested sister group relationship of Etia and mouthbrooding tilapiines with the remaining haplotilapiines. The latter are consistently placed in eight monophyletic clades over all datasets and analyses, but several dichotomous phylogenetic relationships appear compromised by cytonuclear discordant phylogenetic signal. Based on these results as well as on extensive morphological evidence we propose a novel generic and suprageneric classification including a (re-)diagnosis of 20 haplotilapiine cichlid genera and nine tribes. New tribes are provided for the former subgenera Coptodon Gervais, 1853, Heterotilapia Regan, 1920 and Pelmatolapia Thys van den Audenaerde, 1969, in addition for ". Tilapia" joka, Tilapia sensu stricto and Chilochromis, Etia, Steatocranus sensu stricto, the mouthbrooding tilapiines and for a clade of West African tilapiines. © 2013 Elsevier Inc..

Jorger K.M.,Bavarian State Collection of Zoology | Stoger I.,Bavarian State Collection of Zoology | Kano Y.,University of Tokyo | Fukuda H.,Okayama University | And 2 more authors.
BMC Evolutionary Biology | Year: 2010

Background. A robust phylogenetic hypothesis of euthyneuran gastropods, as a basis to reconstructing their evolutionary history, is still hindered by several groups of aberrant, more or less worm-like slugs with unclear phylogenetic relationships. As a traditional "order" in the Opisthobranchia, the Acochlidia have a long history of controversial placements, among others influenced by convergent adaptation to the mainly meiofaunal habitats. The present study includes six out of seven acochlidian families in a comprehensive euthyneuran taxon sampling with special focus on minute, aberrant slugs. Since there is no fossil record of tiny, shell-less gastropods, a molecular clock was used to estimate divergence times within Euthyneura. Results. Our multi-locus molecular study confirms Acochlidia in a pulmonate relationship, as sister to Eupulmonata. Previous hypotheses of opisthobranch relations, or of a common origin with other meiofaunal Euthyneura, are clearly rejected. The enigmatic amphibious and insectivorous Aitengidae incerta sedis clusters within Acochlidia, as sister to meiofaunal and brackish Pseudunelidae and limnic Acochlidiidae. Euthyneura, Opisthobranchia and Pulmonata as traditionally defined are non-monophyletic. A relaxed molecular clock approach indicates a late Palaeozoic diversification of Euthyneura and a Mesozoic origin of the major euthyneuran diversity, including Acochlidia. Conclusions. The present study shows that the inclusion of small, enigmatic groups is necessary to solve deep-level phylogenetic relationships, and underlines that "pulmonate" and "opisthobranch" phylogeny, respectively, cannot be solved independently from each other. Our phylogenetic hypothesis requires reinvestigation of the traditional classification of Euthyneura: morphological synapomorphies of the traditionally defined Pulmonata and Opisthobranchia are evaluated in light of the presented phylogeny, and a redefinition of major groups is proposed. It is demonstrated that the invasion of the meiofaunal habitat has occurred several times independently in various euthyneuran taxa, leading to convergent adaptations previously misinterpreted as synapomorphies. The inclusion of Acochlidia extends the structural and biological diversity in pulmonates, presenting a remarkable flexibility concerning habitat choice. © 2010 Jörger et al; licensee BioMed Central Ltd.

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