Received: 23 September 2013 / Accepted: 19 February 2014 / Published online: 23 September 2013
Morphological and chemical analysis of male scent organs in the butterfly genus Pyrgus (Lepidoptera: Hesperiidae)Download PDFAbstract
Chemical communication in the family Hesperiidae (Lepidoptera) is practically unstudied, even though this group includes approximately 4,000 species and represents a fifth of the world’s butterfly fauna. We present the first comparative morphological and chemical analysis of scent organs for nine species in the genus Pyrgus, the most species-rich hesperiid genus in the Palearctic region. Our results show that the morphology of the two main male scent organs—the costal fold and the tibial tufts—does not differ between species. The chemical analyses detected a total of 125 different compounds exclusively present in these organs. We document great interspecific differences and much narrower intraspecific variability in the chemical profiles. The dynamics of chemical versus genetic distances indicate two different phases: a faster (but more variable) initial chemical divergence at lower genetic divergences (probably related to speciation) and a slower but more constant differentiation (drift). As a result most species can be identified based on their chemical profiles, except for a closely related species pair (P. malvae/P. malvoides) for which hybridisation is common in the contact zone. Our results suggest that the Hesperiidae is a group with great potential for the study of chemical communication that deserves further attention.
Received: 29 August 2013 / Accepted: 08 January 2014 / Published online: 29 August 2013
Inferring the accumulation of morphological disparity in epiphyllous liverwortsDownload PDFAbstract
Phylogenetic studies of lineages growing in extreme environments have frequently recovered evidence not only of high level of homoplasy but also of discordance of morphological disparity and species diversity. It has been suggested that this divergence may be caused by developmental constraints and/or natural selection. Here we explored these hypotheses by inferring the phenotypic evolution of the derived liverwort genus Cololejeunea. These liverworts occur preferentially on the surface of leaves or other aerial parts of vascular plants growing in wet forests. The evolution of 12 morphological characters was studied using a phylogenetic framework comprising 70 species of Cololejeunea. The phylogeny was reconstructed using DNA sequences of one nuclear and two plastid regions and enabled the inference of the evolution of the studied morphological characters by determining the frequency of homoplasy. Mantel tests were used to test for correlations of morphological disparity × species diversity and morphological disparity × epiphytism. The phylogenetic informativeness of each binary character was estimated by the D metric of the Fritz and Purvis test, and the relationship between each character and epiphytism was inferred by Pearson’s coefficient. We evaluated the morphospace occupation using principal coordinate analyses. Our results not only recovered high levels of homoplasy but also weak correlations of morphological disparity and species diversity. Morphological disparity was not linked to epiphytism, although positive or negative relationships between some characters and epiphytism were found. The Brownian model of character evolution was not rejected for the studied morphological disparity in Cololejeunea with the exception of asexual propagules. The observations support the prediction that iterative evolution in a well-defined morphospace may result in rampant homoplasy and the observed divergence of disparity and diversity.
Received: 10 January 2013 / Accepted: 10 December 2013 / Published online: 10 January 2013
Impact of habitat and life trait on character evolution of pallial eyes in Pectinidae (Mollusca: bivalvia)Download PDFAbstract
Pectinidae, a large group of marine bivalves comprising more than 300 species worldwide, inhabit a diverse array of habitats, enabling an enormous radiation, and yielding many different life forms and adaptations. This apparent diversity led to the distinction of ecotypes based on shell morphology and lifestyle. Eyes in Pectinidae (Bivalvia, Pteriomorphia) have long sparked scientific interest and have been described for various species over the past two centuries. These eyes are morphologically and functionally highly complex. Despite this complexity, studies have focused mostly on functional aspects with only few examining the relationships associated with different environmental or evolutionary traits. Here, the pallial eye structure within the Pectinidae was examined using Masson Goldner Trichrom staining, and ancestral character estimation with BayesTraits was performed to reconstruct macro-evolutionary patterns. To evaluate the connection of substrate type and lifestyle to the evolution of eyes, we compared eyes within the major subgroups of Pectinidae while considering the different lifestyles and substrate types as well as different depth ranges. The results indicate a tendency towards a taxon-/clade-specific evolution in respect to characters such as the cornea and lens while depth specific adaptations occur mainly in the light sensitive compartments of the retina. Successive reduction of eyes seems to occur from shallow to deep water species and ends in a total reduction of all structures in deep sea species.
Received: 28 July 2013 / Accepted: 01 February 2014 / Published online: 28 July 2013
How might sea level change affect arthropod biodiversity in anchialine caves: a comparison of Remipedia and Atyidae taxa (Arthropoda: Altocrustacea)Download PDFAbstract
Sea level change influences biodiversity of endemic cave fauna to varying degrees. In anchialine systems, a marine layer flows under less saline layers, each with differing associated fauna. We assess the role of present and historic (last glacial maximum – 18,000 years ago) distance from the ocean in determining species richness and phylogenetic diversity patterns for two groups of anchialine crustaceans: the marine-restricted Remipedia and a subset of groundwater-inhabiting atyid shrimp with greater tolerance for salinity variation. We calculated species richness and phylogenetic diversity per cave based on records of remipede and atyid diversity at 137 locations in the Yucatán Peninsula, Caribbean, Australia, and the Canary Islands. After calculating the distance of each cave’s surface opening from the past and present shoreline, we evaluated how species richness and phylogenetic diversity change with distance from the present and historic ocean. Remipede species richness and phylogenetic diversity declined rapidly with distance from the ocean. Ninety-five percent of the remipedes surveyed were located within 7 km of the present ocean and 18 km of the historic ocean. Atyid species richness and phylogenetic diversity declined more slowly with distance from the ocean than that of remipedes. Atyid shrimp were also distributed over a broader range: 95 % were located within 100 km of the present ocean and 240 km of the historic ocean. Our findings indicate that coastal geomorphology and salinity tolerance influence a clade’s distribution with respect to its distance from the ocean. We also report a possible latent response to sea level change.
Received: 30 April 2014 / Accepted: 15 June 2014 / Published online: 30 April 2014
Rediscovery of an internal organ in heart urchins (Echinoidea: Spatangoida): morphology and evolution of the intestinal caecumDownload PDFAbstract
A thorough understanding of the sea urchin (Echinodermata: Echinoidea) digestive tract anatomy is a prerequisite for the correct interpretation of physiological and biomechanical analyses focusing on the gut architecture of this ecologically important group of marine invertebrates. A number of studies have addressed the general arrangement of the sea urchin digestive tract, but accessory structures such as siphons and caeca have received less attention. Two studies carried out to analyze the gut physiology of various marine invertebrates briefly mentioned the presence of a previously undescribed pouch in the posterior digestive tract of the heart urchin (Echinoidea: Spatangoida) species Brisaster latifrons. Dissections, histological, and magnetic resonance imaging data, as well as three-dimensional reconstructions corroborate these findings. The novel structure—here termed the intestinal caecum—is suspended by a thin mesentery within a coil formed by the posteriormost part of the intestine. The kidney-shaped organ constitutes a derivative of the intestine, to which it is laterally connected through a narrow canal. In contrast to the sediment-packed main digestive tract, the intestinal caecum is filled with liquid and a flocculent mass. The organ’s histology is characterized by a thin connective tissue layer with only a small number of hemal lacunae and muscle fibers, as well as an inner simple columnar epithelium that contains numerous dark-brown vacuoles. The intestinal caecum is found exclusively among members of the Schizasteridae (Spatangoida: Paleopneustina). Specifically, the organ is present in selected species of the genera Abatus, Brisaster, and Tripylaster, but not in the other seven schizasterid genera analyzed. The intestinal caecum is not homologous to the sometimes equally named accessory structure present in the posterior digestive tract of other spatangoid taxa such as Echinocardium or Heterobrissus. Consequently, the previously introduced term recto-intestinal caecum is here applied for this latter organ. No correlation could be found between the absence or presence of the intestinal caecum and any known biological or morphological characteristics of schizasterid heart urchins. The distribution of the organ among schizasterids supports a close relationship of the genera Brisaster, Tripylaster, and selected species of Abatus.
Received: 26 July 2013 / Accepted: 29 October 2013 / Published online: 26 July 2013
Coevolution of male and female genitalia in stalk-eyed flies (Diptera: Diopsidae)Download PDFAbstract
The present study investigates the coevolution of a particular male genital process and the female spermathecal ducts in a clade of stalk-eyed flies (Diptera, Diopsidae) and debates the underlying evolutionary mechanisms. The fine morphology and interaction of the male and female genitalic structures are reconstructed from serial sections of mating pairs in one of the species. It is found that the male genital process traverses the common spermathecal duct to enter the base of one of the separate spermathecal ducts during the mating. Spermatozoa and accessory secretions are not transferred through the male genital process but can be discharged only from the male gonopore near its base. A detailed morphometric study reveals low intraspecific variation and hypoallometry of the male genital process. Across 17 species studied comparatively, the lengths of the male genital process and the female common and separate spermathecal ducts are highly variable. The length of the male genital process is correlated significantly with that of the female common spermathecal duct, but not with that of the separate spermathecal ducts. Based on the combined evidence it is concluded that the male genital process and the female common spermathecal duct have coevolved, and that sexual selection by cryptic female choice constitutes a possible and parsimonious explanation for their coevolution. Alternative or additional explanations in terms of sexually antagonistic coevolution cannot be ruled out conclusively, but are not supported by the available evidence.
Received: 12 March 2014 / Accepted: 28 July 2014 / Published online: 12 March 2014
Climate-induced shifts in the niche similarity of two related spadefoot toads (genus Pelobates)Download PDFAbstract
Of the four species encompassing the genus Pelobates, only two overlap along a narrow contact zone, i.e., Pelobates fuscus and Pelobates syriacus. Our study investigated the shifts in niche similarity of these two closely related species from the Last Interglacial towards the end of the twenty-first century. We computed climatic suitability models using Maxent and projected them onto future and past climates. We used fossil occurrences to test the predictive accuracy of past projections. Niche similarity was assessed between the studied species using Schoener’s D index and a background similarity test. Finally, we evaluated niche differentiation by contrasting the species occurrences using a logistic regression analysis. The ecological niches are slightly extended outside the present geographical ranges in the Caucasus and the Balkans, south for P. fuscus and north and west for P. syriacus, suggesting that their present distribution is not at equilibrium with the climate. The Last Interglacial distribution of P. fuscus included British Isles and broad areas in western, central, and northern Europe, while P. syriacus extended northwards in the Balkans. The validation with fossil records revealed good predictive performance (omission error = 4.1 % for P. fuscus and 16.6 % for P. syriacus). During the Last Glacial Maximum, climatic suitability persisted in refugia in southern Europe, Pannonian Basin, and Caucasus for P. fuscus, and Israel, southern Balkans, and Caucasus for P. syriacus. Present potential distributions revealed a low similarity of species’ ecological niches, comparable with Last Interglacial, but projections towards 2080 revealed a sharp increase.
Received: 23 February 2013 / Accepted: 31 July 2013 / Published online: 23 February 2013
New insights into the systematics and molecular phylogeny of the Malagasy snake genus Liopholidophis suggest at least one rapid reversal of extreme sexual dimorphism in tail lengthDownload PDFAbstract
The pseudoxyrhophiine snake genus Liopholidophis Mocquard, 1904 (family Lamprophiidae) is endemic to Madagascar and according to its present definition comprises six medium-sized, terrestrial and diurnal snake species, most of which are characterised by an unusual and extreme sexual dimorphism in tail length. We performed molecular phylogenetic analyses using nucleotide sequences of three mitochondrial genes (16S rRNA, cytochrome b and cytochrome oxidase I) and one nuclear gene (c-mos) for all described and two additional species newly described herein. The two new species are very small sized (total length: 234–312.5 mm), have comparatively short tails and a reduced number of dorsal scale rows (15 at midbody), the lowest value among all non-scolecophidian snakes of Madagascar. Both species are secretive or rare, and they have a reddish belly in life that fades in preservative. In terms of colouration and morphology, they are most similar to each other and furthermore to Liopholidophis rhadinaea. Together with this species and L. dimorphus, they form a well-supported clade. Liopholidophis baderi sp. nov. from central eastern Madagascar is characterised by 149–158 ventrals and 71–77 subcaudals, whereas the similar L. oligolepis sp. nov. from the northeast has even fewer ventrals (137) and subcaudals (54). The phylogenetic tree suggests that the tail length dimorphism in the genus Liopholidophis has evolved in a complex pattern including at least one reversal. The phylogenetic position of the two new dwarf species indicates that both the absence of extreme sexual dimorphism in tail length and their body size reduction are derived and probably correlated features. Also the close phylogenetic relationships between the long-tailed L. sexlineatus and the similar but relatively short-tailed L. varius demonstrate that dimorphism in tail length can be strongly mitigated in short evolutionary time periods.
Received: 06 March 2013 / Accepted: 06 July 2013 / Published online: 06 March 2013
DNA barcoding of brown Parmeliae (Parmeliaceae) species: a molecular approach for accurate specimen identification, emphasizing species in GreenlandDownload PDFAbstract
Warming of Arctic and alpine regions has a substantial impact on high-altitude/-latitude ecosystems. Shifting biomes due to climate change may lead to adjustments in species distributions and potential extinctions. Therefore, detailed monitoring is requisite to assess biologically meaningful shifts in community composition and species distributions. Some Arctic-alpine lichens have been shown to be particularly sensitive to climatic shifts associated with global change. However, accurate identification of lichenized fungal species remains challenging and may limit the effective use of lichens in climate change research. Given the inherent difficulties in accurate identification of lichenized fungi and the potential value of efficient identifications for bio-monitoring research, we investigated the utility of DNA barcode identification of the 13 brown Parmeliae (Ascomycota) species occurring in Greenland. For these species, we assessed monophyly and genetic distances using the nuclear ribosomal internal transcribed spacer region (ITS), the standard DNA barcode for fungi. We also compared intraspecific distance values to a proposed intra-interspecific threshold value for Parmeliaceae to identify nominal taxa potentially masking previously unrecognized diversity. Our results indicated that the 13 brown Parmeliae species occurring in Greenland can be successfully discriminated using the ITS region. All phenotypically circumscribed species were recovered as well-supported, monophyletic clades. Furthermore, our data supported a barcode gap among congeners for all brown Parmeliae species investigated here. However, high intraspecific genetic distances suggest the potential for previously unrecognized species-lineages in at least five species: Melanelia agnata, M. hepatizon, Montanelia disjuncta, M. panniformis, and M. tominii. Our research facilitates effective, long-term bio-monitoring of climate change in Greenland using lichens by providing accurate molecular identification of brown Parmeliae specimens.
Received: 13 February 2014 / Accepted: 21 April 2014 / Published online: 13 February 2014
Adding depth to line artwork by digital stippling—a step-by-step guide to the methodDownload PDFAbstract
Vector-based software has revolutionized scientific illustrating and is well established in taxonomy. However, simple line drawings lack depth information. Shading techniques, such as stippling—the application of dots to generate shade—are the methods of choice for simulating shade, structure, shape, and texture. In this paper, a step-by-step guide for digital stippling is presented. Manual stippling offers great flexibility to achieve highly realistic results. A round brush is applied to the line art by tapping. To drastically reduce time consumption and generate homogeneous tinges, a semiautomation was developed: the smallest units of symmetric stippling patterns are stored in a brush library. Using macroinstructions (macros), such stored raw patterns are converted into symmetric repetitive patterns. This way, stippling can be applied quickly and evenly across large areas of the underlying line drawing. These methods come with all the advantages of vector illustrations, such as high scalability, reproducibility and easy correction of strokes that have turned out imperfect.
Received: 29 October 2013 / Accepted: 24 June 2014 / Published online: 29 October 2013
Floral scent and its correlation with AFLP data in Sorbus
Comparisons between floral scent-based and DNA-molecular-based taxonomies are rare, yet such comparisons indicate that scent can provide useful taxonomic information. Here, we correlate the phytochemical differentiation in floral scent to the DNA-molecular-based differentiation in the genus Sorbus. Inflorescence scent patterns of the apomictic and endemic Sorbus latifolia microspecies Sorbus franconica, Sorbus adeana, and Sorbus cordigastensis originated by hybridization as well as their parental taxa Sorbus aria agg. and Sorbus torminalis were investigated with the dynamic headspace method. The scent data (presence/absence of compounds) were used to construct an UPGMA tree, to calculate a similarity matrix, and to correlate them with the published amplified fragment length polymorphism (AFLP) data of the same individuals, populations, and taxa. Flow cytometry was used to estimate the DNA-ploidy level of the taxa. Scent analyses showed a total of 68 substances, among them aromatic compounds, terpenoids, aliphatics, and nitrogen-containing compounds. The scent patterns were taxon-specific, and the number of scent components differed among taxa. The correlations with the published AFLP data on population and individual level are highly significant, indicating that the scent and AFLP data are highly congruent in the plants studied. Scent therefore provides useful taxonomic characters in Sorbus.
Received: 22 May 2013 / Accepted: 04 November 2013 / Published online: 22 May 2013
Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organismsDownload PDFAbstract
Reflection spectra obtained from hyperspectral imaging can be used as a bio-optical taxonomic identification tool if the pigment composition and the corresponding optical absorption signatures of an organism are known. In this study we elucidate species-specific absorption and corresponding reflection signatures of marine organisms and discuss optical fingerprints from underwater hyperspectral imaging (UHI) for future automated identification of organisms on the seafloor. When mounted on underwater robots, UHI has the potential to be a time- and cost-efficient identification and mapping method covering large areas over a short time. Hyperspectral imaging in vivo and in situ were used to obtain species-specific reflection signatures (optical fingerprints). High performance liquid chromatography, liquid chromatography–mass spectroscopy and nuclear magnetic resonance were used for pigment identification and to obtain species-specific absorption signatures of four marine benthic species; the spoonworm Bonellia viridis, and the sponges Isodictya palmata, Hymedesmia paupertas and Hymedesima sp. Species-specific optical fingerprints based on a UHI-based reflectance signature were verified successfully in the organisms investigated.
Received: 28 April 2014 / Accepted: 16 June 2014 / Published online: 28 April 2014
Are copepods secondary hosts of Cycliophora?Download PDFAbstract
Ever since the first observations in the late 1960s, Cycliophora were found exclusively living epizoically on lobsters belonging to the family Nephropidae. The complex cycliophoran life cycle, with alternation of asexual and sexual generations, takes place only in the microhabitat provided by the host mouthparts. Herein, we report the first evidence of a symbiotic relationship between cycliophorans and organisms other than nephropid lobsters, namely, the harpacticoid copepods. Two specimens of copepods associated with cycliophoran life cycle stages were collected from the segmental mouthparts of a European lobster, Homarus gammarus. One of the copepods carried two feeding stages with long stalks, which probably belong to an undescribed Symbion sp., while the other copepod was found bearing an undetermined settled stage. We discuss the implications of these novel observations for the understanding of the Cycliophora life cycle and their dispersion abilities.
Received: 27 November 2013 / Accepted: 04 February 2014 / Published online: 27 November 2013
Where are you from, stranger? The enigmatic biogeography of North African pond turtles (Emys orbicularis)Download PDFAbstract
The European pond turtle (Emys orbicularis) is a Nearctic element in the African fauna and thought to have invaded North Africa from the Iberian Peninsula. All North African populations are currently identified with the subspecies E. o. occidentalis. However, a nearly range-wide sampling in North Africa used for analyses of mitochondrial and microsatellite DNA provides evidence that only Moroccan populations belong to this taxon, while eastern Algerian and Tunisian pond turtles represent an undescribed distinct subspecies. These two taxa are most closely related to E. o. galloitalica with a native distribution along the Mediterranean coast of northern Spain through southern France to western and southern Italy. This group is sister to a clade comprising several mitochondrial lineages and subspecies of E. orbicularis from Central and Eastern Europe plus Asia, and the successive sisters are E. o. hellenica and E. trinacris. Our results suggest that E. orbicularis has been present in North Africa longer than on the Iberian Peninsula and that after an initial invasion of North Africa by pond turtles from an unknown European source region, there was a phase of diversification in North Africa, followed by a later re-invasion of Europe by one of the African lineages. The differentiation of pond turtles in North Africa parallels a general phylogeographic paradigm in amphibians and reptiles, with deeply divergent lineages in the western and eastern Maghreb. Acknowledging their genetic similarity, we propose to synonymize the previously recognized Iberian subspecies E. o. fritzjuergenobsti with E. o. occidentalis sensu stricto. The seriously imperiled Moroccan populations of E. o. occidentalis represent two Management Units different in mitochondrial haplotypes and microsatellite markers. The conservation status of eastern Algerian pond turtles is unclear, while Tunisian populations are endangered. Considering that Algerian and Tunisian pond turtles represent an endemic taxon, their situation throughout the historical range should be surveyed to establish a basis for conservation measures.
Received: 27 October 2012 / Accepted: 31 July 2013 / Published online: 27 October 2012
Allopolyploid origin of the Balkan endemic Ranunculus wettsteinii (Ranunculaceae) inferred from nuclear and plastid DNA sequencesDownload PDFAbstract
The Balkan Peninsula, characterized by high rates of endemism, is recognised as one of the most diverse and species-rich areas of Europe. However, little is known about the origin of Balkan endemics. The present study addresses the phylogenetic position of the Balkan endemic Ranunculus wettsteinii, as well as its taxonomic status and relationship with the widespread R. parnassiifolius, based on nuclear DNA (internal transcribed spacer, ITS) and plastid regions (rpl32-trnL, rps16-trnQ, trnK-matK and ycf6-psbM). Maximum parsimony and Bayesian inference analyses revealed a well-supported clade formed by accessions of R. wettsteinii. Furthermore, our phylogenetic and network analyses supported previous hypotheses of a likely allopolyploid origin for R. wettsteinii between R. montenegrinus and R. parnassiifolius, with the latter as the maternal parent.
Received: 06 May 2013 / Accepted: 09 August 2013 / Published online: 06 May 2013
Cryptic diversity in the Mediterranean Temnothorax lichtensteini species complex (Hymenoptera:Formicidae)Download PDFAbstract
In this paper we provide insight into the cryptic diversity and biogeographic patterns of a widely distributed Mediterranean ant species, Temnothorax lichtensteini (Bondroit Annales de la Société Entomologique de France 87:1–174, 1918), based on evidence from multiple data sources. An exploratory analysis of morphometric data, combined with sequencing of a 652 bp fragment of the mitochondrial gene for the cytochrome c oxidase subunit I (CO I), indicates the existence of three distinct lineages. Divergence of two recognised genetic lineages, Western and Eastern Mediterranean clusters, is not reliably supported by confirmatory analysis of morphological data. We hypothesise that this reflects incomplete speciation in separate glacial refugia and therefore discuss only biogeographic aspects of these two parapatric populations. However, the third, Peloponnese, lineage is divergent in both morphology and CO I sequences and its separation from the other two lineages is convincingly confirmed. For this lineage we assume a completed speciation and describe the taxon formally as Temnothorax laconicus sp.n., the sister species of T. lichtensteini.
Received: 31 March 2013 / Accepted: 24 October 2013 / Published online: 31 March 2013
Coupling impoverishment analysis and partitioning of beta diversity allows a comprehensive description of Odonata biogeography in the Western MediterraneanDownload PDFAbstract
Islands host a subset of organisms occurring at their sources, and these assemblages are usually dominated by the most generalistic and dispersive species. In this study, we aim to identify which species are missing on islands and which ecological traits are responsible for differential occurrence. Then, we apply this information to beta diversity analyses. As a study group and area, we selected the Odonata in the Western Mediterranean. Based on the presence/absence of 109 species, we applied a series of analyses at both community and individual species level. The islands of the Balearics, Corsica, Sardinia and Malta are highly impoverished, but Sicily is not. Non-parametric multivariate adaptive regression splines predicted the occurrence of individual species on each island. Principal component analysis recognised differences between damselflies (Zygoptera) and dragonflies (Anisoptera), but members of the two suborders have similar occurrences on islands, and island occurrence is determined mostly by species’ frequencies at source and by their degree of generalism. Island species predicted correctly to occur on islands showed opposite characteristics to species unpredicted to occur and being present. The similarity pattern highlighted by turnover (Simpson index) is clearer than that obtained by non-partitioned beta diversity (Sørensen index). In fact, indicator value analyses revealed more indicator species for the Simpson compared to Sørensen index, and indicator species from islands where unpredicted to occur by impoverishment analysis. This suggests that island species predicted absent determine most of an island’s turnover pattern, thus encompassing fundamental biogeographic information. Due to their absence on nearest sources, they are also at higher risk of extinction, and deserving of special conservation effort.
Received: 12 June 2013 / Accepted: 25 September 2013 / Published online: 12 June 2013
Affinities of the Canthonini dung beetles of the Eastern Arc MountainsDownload PDFAbstract
The Eastern Arc Mountains (EAM) consist of 13 separate mountain blocks running from southern Kenya through eastern Tanzania in an arc shape. Organisms occurring in the forests of these mountains are known for their high levels of endemism. Some of these organisms have their closest relatives in distant geographic regions. In this study, molecular phylogenetic methods, based on partial sequences of one nuclear (28S) and two mitochondrial (COI and 16S) genes, are used to determine the relationships of three Scarabaeinae genera (tribe Canthonini) endemic to the EAM. Janssensantus and Tanzanolus are found to have a sister relationship within a lineage of south-eastern African genera, while Madaphacosoma’s closest ties are with Oriental and Madagascan taxa Ochicanthon and Epactoides, respectively. Divergence time estimates suggest a Miocene origin for the ancestral lineages of the three genera with Janssensantus and Tanzanolus separating in the Pleistocene. Our results provide evidence for a Madagascan origin for the EAM genera.
Received: 24 October 2013 / Accepted: 12 March 2014 / Published online: 24 October 2013
Parallel and convergent diversification in two northern hemispheric species-rich Carex lineages (Cyperaceae)Download PDFAbstract
Carex species are dominant and abundant plants in boreal and arctic landscapes, typically covering large wetland areas. Most of these vegetation-characteristic species are from Carex sections Phacocystis and Vesicariae, frequently growing together, but also forming monodominant stands. Here we study these species in a phylogenetic framework to infer whether this co-occurrence pattern results from convergent evolution. In both sections, we observed a Northern clade consisting only of arctic to boreal species, a Mixed clade of northern and more southerly distributed species and a Southern grade of species mainly from temperate or further southern zones. The species of the Northern clades of both sections that are the focus of the study may be of similar young age and are rather equally diversified in terms of molecular divergence and morphology, suggesting a replicate adaptive radiation in boreal to arctic habitats. Morphological characters possibly linked with functional importance are not significantly different between the respective clades of the two sections, whereas reproductive structures may be phylogenetically constrained. The evolution of salt tolerance and ongoing diversification in the Northern clade of sect. Phacocystis suggests that the observed replicate adaptive radiation might be a transitional state in the diversification of species and may explain why such radiations are so rarely documented.
Received: 18 January 2013 / Accepted: 04 September 2013 / Published online: 18 January 2013
Integrative taxonomy of four Clathrina species of the Adriatic Sea, with the first formal description of Clathrina rubra Sarà, 1958Download PDFAbstract
The taxonomy of the class Calcarea has long relied on histological and morphological characters, with a few molecular studies done. In character-poor genera, such as Clathrina, an integrative taxonomy, associating morphological and molecular tools, greatly aids in the species identification. In this study, we describe four Clathrina species from the northern Adriatic Sea using morphology and DNA sequences together with observations on their ecology. Clathrina clathrus and Clathrina blanca have been previously reported for the Adriatic Sea; however, it is the first time that a DNA sequence of C. blanca has been obtained. Clathrina cf. hondurensis, a Caribbean species, is being reported in the Adriatic Sea for the first time, and we present the first description and DNA sequence of Clathrina rubra, a red species originally mentioned from Naples.
Received: 15 March 2013 / Accepted: 04 September 2013 / Published online: 15 March 2013
3D-microanatomy and histology of the hydrothermal vent gastropod Lurifax vitreus Warén & Bouchet, 2001 (Heterobranchia: Orbitestellidae) and comparisons with EctobranchiaDownload PDFAbstract
Up to now, the internal anatomy of representatives of only two of three recent genera of the Orbitestellidae have been described. Herein, a species of the third genus, Lurifax vitreus from hydrothermal vent sites of the North Atlantic, is examined on the basis of semi-thin sections. Data on three-dimensional (3D)-anatomy and histology are provided in order to increase knowledge of the family. In addition, the original serial sections of Orbitestella wareni and Microdiscula cf. subcanaliculata of the original paper by Ponder (Journal of Molluscan Studies 56:515–532, 1990a) were reinvestigated and compared with Lurifax vitreus. Although Lurifax vitreus is significantly larger than the two former genera, it is again devoid of a gill but shows opponent ciliary stripes and a pallial tentacle. Most orbitestellid characters reflect plesiomorphic conditions among the Heterobranchia; autapomorphies of the family include an orthostrophic protoconch, massive jaws, a diagnostic radula type, paired posterior pedal glands with a common opening, and a pedally innervated copulatory organ. In agreement with actual molecular trees, our data suggest a placement of Orbitestellidae as basic Heterobranchia outside of Ectobranchia (Valvatoidea).
Received: 22 January 2013 / Accepted: 30 August 2013 / Published online: 22 January 2013
Community structure and species diversity of Harpacticoida (Crustacea: Copepoda) at two sites in the deep sea of the Angola Basin (Southeast Atlantic)Download PDFAbstract
The aim of this study was to evaluate compositional differences between harpacticoid (Crustacea, Copepoda) assemblages at two widely separated abyssal locations. During the DIVA 1 cruise of RV METEOR (July/August 2000) to the Angola Basin (Southeast Atlantic), two deep-sea stations, approximately 300 nautical miles apart (Stations 325 and 346), were sampled repeatedly by Multicorer (MUC). For quantitative analyses, 5 MUC samples were selected at random from each of 15 deployments at both stations, totalling 75 cores. Across the study, 7,081 Harpacticoida specimens were encountered and of these 31.4 % were adults and could be analysed to species level: 682 species were identified, with 99.3 % new to science. At northern Station 346, a total of 600 species were recorded—the highest harpacticoid species number ever recorded for a single deep-sea locality. Most species (56 %) were represented by singletons. Multivariate tests identified significant differences between community compositions at the two stations. Diversity, species richness and species density were higher at Station 346, whilst taxonomic distinctness, evenness, and rarefaction were similar between stations. Regression and correlation analyses showed that the difference in species diversity was best explained by species densities rather than species richness. Under-sampling due to low densities was an issue at the southern Station 325. Nevertheless, our study demonstrated significant differences in regional-scale harpacticoid community structures within a single deep-sea basin that would usually be considered a uniform and stable habitat. These observed differences are thought to reflect differences in food availability at the two stations.
Received: 26 February 2014 / Accepted: 24 August 2014 / Published online: 26 February 2014
Deep-sea Kinorhyncha: two new species from the Guinea Basin, with evaluation of an unusual male featureDownload PDFAbstract
Two new species of homalorhagid kinorhynchs from the deep-sea Guinea Basin are described. Pycnophyes nubilis sp. nov. is easily recognized by the presence of paradorsal setae on segment 1; middorsal processes on segments 1–10, progressively increasing in length towards the posterior segments; and middorsal process on segment 10 extending over the last trunk segment. Pycnophyes farinellii sp. nov. is distinguished by middorsal elevations on segments 2–9 and laterodorsal and ventromedial setae on segments 2 and 9 only. Moreover, males of the latter species lack ventromedial tubes on segment 2—a very uncommon feature among the genus. The systematic significance of this character is discussed in detail.
Received: 12 February 2013 / Accepted: 31 July 2013 / Published online: 12 February 2013
Flashback and foreshadowing—a review of the taxon OpisthobranchiaDownload PDFAbstract
Opisthobranchia have experienced an unsettled taxonomic history. At the moment their taxonomy is in state of dramatic flux as recent phylogenetic studies have revealed traditional Opisthobranchia to be paraphyletic or even polyphyletic, allocating some traditional opisthobranch taxa to other groups of Heterobranchia, e.g. Pulmonata. Here we review the history of Opisthobranchia and their subgroups, explain their traditionally proposed relationships, and outline the most recent phylogenetic analyses based on various methods (morphology, single gene and multiple gene analyses, as well as genomic data). We also present a phylogenetic hypothesis on Heterobranchia that, according to the latest results, represents a consensus and is the most probable one available to date. The proposed phylogeny supports the Acteonoidea outside of monophyletic Euthyneura, the basal euthyneuran split into Nudipleura (Nudibranchia plus Pleurobranchoidea) and the recently established taxon Tectipleura. The latter divides into the Euopisthobranchia, containing most of the major traditional opisthobranch clades, and the Panpulmonata, with a mix of the former opisthobranch, putative allogastropod and pulmonate taxa. This “new euthyneuran tree” rejects the traditional taxa Opisthobranchia and Pulmonata, and, in particular, has profound implications for preconceived textbook scenarios of opisthobranch and pulmonate evolution, which must now be reconsidered. In the absence of systematic barriers, research communities—which have traditionally investigated marine and non-marine heterobranchs separately—need to interact and finally merge for the sake of science.
Received: 18 July 2013 / Accepted: 12 February 2014 / Published online: 18 July 2013
A phylogeny of softshell turtles (Testudines: Trionychidae) with reference to the taxonomic status of the critically endangered, giant softshell turtle, Rafetus swinhoei
Several important aspects of the evolution of the softshell turtle (family Trionychidae) have not been addressed thoroughly in previous studies, including the pattern and timing of diversification of major clades and species boundaries of the critically endangered Shanghai Softshell Turtle, Rafetus swinhoei. To address these issues, we analyzed data from two mitochondrial loci (cytochrome b and ND4) and one nuclear intron (R35) for all species of trionychid turtles, except Pelochelys signifera, and for all known populations of Rafetus swinhoei in Vietnam and one from China. Phylogenetic analyses using three methods (maximum parsimony, maximum likelihood, and Bayesian inference) produce a well resolved and strongly supported phylogeny. The results of our time-calibration and biogeographic optimization analyses show that trionychid dispersals out of Asia took place between 45 and 49 million years ago in the Eocene. Interestingly, the accelerated rates of diversification and dispersal within the family correspond surprisingly well to global warming periods between the mid Paleocene and the early Oligocene and from the end of the Oligocene to the mid Miocene. Our study also indicates that there is no significant genetic divergence among monophyletic populations of Rafetus swinhoei, and that previous taxonomic revision of this species is unwarranted.
Received: 13 December 2013 / Accepted: 23 April 2014 / Published online: 13 December 2013
The Caucaso-Anatolian slave-making ant Myrmoxenus tamarae (Arnoldi, 1968) and its more widely distributed congener Myrmoxenus ravouxi (André, 1896): a multidisciplinary comparison (Hymenoptera: Formicidae)Download PDFAbstract
A small minority of the presently recognized ∼12,500 species of ants are slave-makers, which permanently depend on the help of “slave workers,” that is workers of other ant species, which they pillage as brood from their nests in well-organized slave raids. The genus Myrmoxenus is one of the most species-rich taxa of slave-making ants, but individual species are often not well-delimited. Here, we compare behavior, morphometry, and nuclear and mtDNA sequences between two taxa of Myrmoxenus: Myrmoxenus tamarae (Arnoldi, 1968), known only from its type locality in Georgia, and the wide-spread M. ravouxi (André, 1896) to determine if the former might simply represent a Caucasian variant of the latter. Workers of the two taxa differed clearly in locomotor activity and slightly also in morphometry, while genetic investigations with nuclear and mitochondrial genes revealed only a weak differentiation. Given that Myrmoxenus appears to be a genus with a relatively recent radiation, we suggest to conservatively keep the present taxonomic situation with M. ravouxi and M. tamarae as separate species. The latter would then include specimens from Eastern Turkey and probably also Ukraine. Further studies, in particular in Greece and Turkey, might help to clarify the status of these endangered ants.
Received: 14 December 2012 / Accepted: 26 June 2013 / Published online: 14 December 2012
Immature stages of Meiosimyza Hendel 1925 and related genera (Diptera, Lauxaniidae)Download PDFAbstract
The immature stages of Holometabolan insects can provide valuable data both for taxonomy and phylogeny, but they are well known only for a negligible proportion of the described species. Scanning electron microscopy (SEM) analysis of all preimaginal stages of the lauxaniid species Meiosimyza decempunctata (Fallén 1820), M. platycephala (Loew 1847), M. rorida (Fallén 1820), M. subfasciata (Zetterstedt 1838), Tricholauxania praeusta (Fallén 1820) and Aulogastromyia anisodactyla (Loew 1845) is presented for the first time. Detailed images of eggs and all three larval instars are provided along with illustrations of the cephaloskeleton and photos of puparia. The egg is rather simple, white, with developed longitudinal ridges. The body integument of all larval instars is smooth and uniform across species. The cephaloskeleton is slender; the mouth hooks are parallel, subhypostomal sclerites are arched and fusing to a ventral bridge. The puparium is brownish, oval, without calcareous deposits. Generally, the morphology of larvae and puparia is very conservative. On the other hand, the eggs show considerable degree of interspecific variability.
Received: 17 June 2013 / Accepted: 04 December 2013 / Published online: 17 June 2013
Climatic correlates of body size in European tenebrionid beetles (Coleoptera: Tenebrionidae)Download PDFAbstract
Tenebrionidae are one of the largest families of beetles and are known for their adaptations to hot and dry climates. An increase in body size also increases the volume/surface area ratio, which reduces transpiration, and hence water loss. If an increase in body size is an important adaptation in tenebrionids to cope with increasing aridity, we expect a correlation between body size and climatic gradients in the major tenebrionid clades. Alternatively, we can postulate that arid climates do not drive body size evolution, but rather select, from a wider fauna containing species of any size, those that have larger bodies. In this case we expect that drier regions will host faunas that contain, on average, larger species. To test the first hypothesis, we correlated inter-specific body size variation in the main tenebrionid clades with climatic gradients in Europe. We found only weak trends. To test the second hypothesis, we regressed mean body size of European country faunas against climatic characteristics. We found a strong increase in body size in southern faunas experiencing hot and dry climates. Therefore, increase in body size is not a major adaptation in tenebrionid evolution, but climate is an important filtering factor that determines a prevalence of larger species in southern Europe.
Received: 08 February 2013 / Accepted: 09 July 2013 / Published online: 08 February 2013
Diversity and biogeographical makeup of the dung beetle communities inhabiting two mountains in the Mexican Transition ZoneDownload PDFAbstract
The role of horizontal and vertical colonization on the diversity and integration of the dung beetle fauna of two mountains in the Mexican Transition Zone (Los Tuxtlas and La Chinantla) are analyzed and compared. On each mountain standardized sampling was done using pitfall traps baited with dung and carrion along elevation gradients. On both mountains diversity decreased linearly with increasing elevation. The decrease in the number of genera and species was not different between mountains, but the cumulative total number for both taxonomic levels was significantly higher on La Chinantla. There, three well-defined groups were identified for which species turnover was mainly a result of species gain. On Los Tuxtlas there was no evident grouping pattern, and species turnover was determined by species loss. For both mountains the dominant biogeographic distribution pattern was Neotropical; however, at the higher elevations of La Chinantla, a clear replacement by lineages of Holarctic affinity was observed. We suggest that for La Chinantla—a mountain that is geographically connected to the Sierra Madre Oriental mountain range and is of ancient geological origin—the processes of horizontal and vertical colonization have had relatively different weights in terms of their effect on the pattern of diversity and the biogeographic integration of the beetle community, while on Los Tuxtlas, the limited role of horizontal colonization appears to be a consequence of its isolation and more recent geological origin. We discuss the potential use of these models for studying the effects of climate change on elevation gradients.
Received: 16 April 2013 / Accepted: 14 May 2014 / Published online: 16 April 2013
Molecular identification and morphological characteristics of native and invasive Asian brush-clawed crabs (Crustacea: Brachyura) from Japanese and German coasts: Hemigrapsus penicillatus (De Haan, 1835) versus Hemigrapsus takanoi Asakura & Watanabe 2005 Download PDFAbstract
Since 1994, Hemigrapsus penicillatus, an Asian brush-clawed shore crab, spreads along Northeast Atlantic coasts. There is evidence that the most recently described and widely accepted sibling species of H. penicillatus, namely Hemigrapsus takanoi, represents the Asian brush-clawed brachyuran crab in Europe. Morphological characteristics are considered insufficient for species discrimination, and molecular analyses were recommended but have to date not been performed in Europe. To clarify the identity of the non-indigenous Asian brush-clawed crab species, which has been invading intertidal alien Crassostrea reefs in the Wadden Sea, we analysed more than 3.5 kpb of mitochondrial and nuclear genes of individuals from invaded German sites and from native Japanese sites. In addition to molecular analyses, we also document key morphological and morphometric characteristics of the same individuals to provide a comparative description. While morphological identification was not confidently feasible, our molecular results confirm the existence of Hemigrapsus takanoi as a closely related species to H. penicillatus and have identified H. takanoi to be the alien brush-clawed crab species in Germany. Furthermore, most of the analysed specimens from Japan and all additional NCBI-listed brush-clawed crabs from Japan, Korea and China which were traditionally classified as H. penicillatus in Asia, are de facto H. takanoi.
Received: 02 February 2014 / Accepted: 05 June 2014 / Published online: 02 February 2014
Mitochondrial evidence for genetic diversity and low phylogeographic differentiation in the Marsh Warbler Acrocephalus palustris (Aves: Acrocephalidae)Download PDFAbstract
We analyzed the levels of genetic variability in a long-distance migratory reed warbler, the Marsh Warbler Acrocephalus palustris, by using nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I gene (COI; 611 nucleotides [nt]). We obtained sequences from 229 individuals from ten sampling sites that include breeding, wintering, and migrating birds. Overall, 44 haplotypes were detected, which reflect high levels of genetic variation in this species, but most of this variation corresponds to individual differences within collecting sites. We also analyzed 829 nt of cytochrome b (cyt b) from 49 selected individuals of different sampling sites to evaluate the reliability of the COI results. Our analyses based on both mtDNA loci could not detect any population subdivision or phylogeographic structure, indicating high levels of gene flow between breeding sites (Nm = 13.69). The split between the Marsh Warbler and its sister species, the Eurasian Reed Warbler Acrocephalus scirpaceus, could be dated for the Lower Pliocene (about 3.8 million years ago). The time to the most recent common ancestor (TMRCA) among Marsh Warbler haplotypes was estimated as 0.45 million years, indicating their bottleneck during the last glacial periods. Low nucleotide diversity, a shallow phylogenetic tree, a star-like haplotype network, and a unimodal mismatch distribution point to a sudden increase of the effective population size (probably after the last glaciation period) and a recent range expansion likely from a single refuge.
Received: 26 February 2013 / Accepted: 21 July 2013 / Published online: 26 February 2013
Isoparactis fionae sp. nov. (Cnidaria: Anthozoa: Actiniaria) from Southern Patagonia with a discussion of the family IsanthidaeDownload PDFAbstract
A new species from Southern Patagonia, Isoparactis fionae sp. nov., is described. Isoparactis fionae sp. nov. differs from other species in the genus by having longitudinal rows of adherent rugae in the column, number of tentacles, cnidae and geographic distribution. We amend the generic position of the previously termed Paraisanthus fabiani (now Isoparactis fabiani comb. nov.), transferring it to Isoparactis as we discovered acontia in the type material of this species. We amend the binomen of Acraspedanthus ferax and use the correct binomen for the species Isoparactis ferax. In addition, we transfer the genus Isoparactis (previously within Bathyphelliidae as Acraspedanthus) to Isanthidae based on molecular evidence and because its diagnosis corresponds better with this family; we amend the diagnosis of Isanthidae accordingly. Finally, we discuss phylogenetic relationships within Isanthidae and among members of the superfamily Metridioidea. Our results show that Isanthidae is composed of derived acontiate sea anemones that have diversified in shallow waters of the Southern Hemisphere and that the family is putatively the sister group of a deep-sea lineage.
Received: 07 November 2013 / Accepted: 11 May 2014 / Published online: 07 November 2013
Species and shape diversification are inversely correlated among gobies and cardinalfishes (Teleostei: Gobiiformes)Download PDFAbstract
Gobies and their relatives are significant components of nearshore marine, estuarine, and freshwater fish faunas in both tropical and temperate habitats worldwide. They are remarkable for their ability to adapt to and diversify in a wide range of environments. Among gobiiform clades, species diversities vary widely, ranging from two species in Kurtidae to more than 1,000 species in Gobiidae. There is also great variation in head and body shape and in environmental preferences (fresh, brackish, or marine habitats). In this study, I used a time-calibrated molecular phylogeny, coupled with morphometric and comparative analyses, to examine evolutionary rates of both speciation and morphological diversification among gobiiform lineages. Projection of the phylogeny onto a shape-derived morphospace shows that Gobioidei is morphometrically distinct from its sister taxon Apogonoidei, but that families within Gobioidei overlap in morphospace. Analysis of species diversification rates indicates that three rate shifts have occurred over the evolutionary history of Gobiiformes. Relative to the other lineages, Kurtidae has exhibited a slowdown in speciation, whereas both Apogonidae and Gobiidae + Gobionellidae have experienced an increase in diversification. Comparative analyses show that in Apogonidae and Gobiidae + Gobionellidae, increased speciation is correlated with diminished rates of morphological diversification, differently manifested in either clade and among the various sublineages. The elevation in speciation rates and diminishment in rates of morphological change in both Apogonidae and the clade Gobiidae + Gobionellidae are correlated with shifts to oceanic habitats from freshwater. This pattern is the complement to that seen across the global radiation of acanthomorph fishes in which a decrease in species diversification is associated with an increase in morphological disparity.
Received: 04 November 2013 / Accepted: 08 April 2014 / Published online: 04 November 2013
Molecular evidence to reconcile taxonomic instability in mahseer species (Pisces: Cyprinidae) of IndiaDownload PDFAbstract
The mahseers are an important group of fishes endemic to Asia with most species considered threatened. Conservation plans to save declining wild populations are hindered by unstable taxonomy, and detailed systematic review could form a solid platform for future management and conservation. D-loop and cytochrome c oxidase I (COI) mtDNA sequences were examined in nine mahseer species of Tor, Neolissochilus, and Naziritor. Pseudogenes amplified in a portion of the species limited the utility of the D-loop region. ABGD analysis, NJ, ML, and MP methods and genetic distance (TrN + I + G) using COI data revealed concordant species delimiting patterns. The three genera were monophyletic, separated as distinct clades (TrN + I + G 0.064 to 0.106), and Naziritor was flagged as a separate genus, distinct from Puntius (TrN + I + G 0.196). Out of seven nominal species known for Tor cogeners from India, only five were recovered with mtDNA data (TrN + I + G 0.000 to 0.037) and two species could not be distinguished with the molecular data set employed. Tor mosal, synonymized as Tor putitora, was rediscovered as a distinct species (TrN + I + G 0.031) based on its type locality. Tor mussulah was confirmed as a separate species (TrN + I + G 0.019 to 0.026). Two valid species, Tor macrolepis and T. mosal mahanadicus, were not distinct from T. putitora (TrN + I + G 0.00). The high divergence with mtDNA data failed to validate T. mosal mahanadicus as a subspecies of T. mosal (TrN + I + G 0.031). Morphological outliers discovered within the distribution range of Tor tor (TrN + I + G 0.022 to 0.025) shared the same lineage with T. putitora (TrN + I + G 0.002 to 0.005), indicating a new extended distribution of the Himalayan mahseer T. putitora in the rivers of the Indian central plateau. The findings indicate the need for integrating molecular and morphological tools for taxonomic revision of the Tor and Naziritor genera, so that taxa are precisely defined for accurate in situ and ex situ conservation decisions.
Received: 26 July 2013 / Accepted: 16 October 2013 / Published online: 26 July 2013
A new type of loriciferan larva (Shira larva) from the deep sea of Shatsky Rise, Pacific OceanDownload PDFAbstract
Loricifera is a phylum of minute animals that live exclusively in marine sediments. A total of 33 species have been described so far in this phylum; however, several more are already known from preliminary observations. Loriciferans are characterised by a complex life cycle, which involves a succession of several adult and larval stages. Here, we describe a new type of loriciferan larval stage: the Shira larva. The gross morphology of this larva is generally similar to that of the most prominent larval type of Loricifera, the so-called Higgins larva. However, the Shira larva possesses a number of unique features, namely (1) a single pair of anteroventral setae is present in the most anterior region of the abdomen, (2) the bases of the anteroventral setae are very large and swollen, (3) the thorax and abdomen are thinner than the introvert and (4) the abdominal region is divided into five sub-regions. Accordingly, we described the new species, Tenuiloricus shirayamai gen. nov. et sp. nov. (incertae sedis). The new findings are discussed from a comparative perspective with the Higgins larva as well as with the fossil of a putative loriciferan larval stage from the Middle Cambrian.