Received: 08 October 2012 / Accepted: 25 January 2013 / Published online: 10 February 2013
Molecular cloning of the trypsin inhibitor from the skin secretion of the Madagascan Tomato Frog, Dyscophus guineti (Microhylidae), and insights into its potential defensive roleDownload PDFAbstract
In this study, we investigate the skin secretion of the Madagascan Tomato Frog, Dyscophus guineti, which is characterized by its peculiarly adhesive and viscous nature, with a view toward the function of the member of the Kunitz/bovine pancreatic trypsin inhibitor family (BPTI) it is known to contain. Using “shotgun” cloning of a skin secretion-derived cDNA library, we obtained the full-length sequence of the respective precursor that encodes this trypsin inhibitor. Furthermore, we demonstrated that this enzyme has inhibitory activity against trypsin, but not against thrombin, and also has no antimicrobial activity. Moreover, we confirm that it appears to be the only bioactive peptide in the skin secretion of this species. Using these observations, we attempt to posit a role for this inhibitor. In particular, we hypothesize that the trypsin inhibitor in D. guineti (and possibly other microhylid frogs) maintains the soluble state of the skin secretion during storage in the glands. Upon discharge of the secretion, the trypsin inhibitor, which occurs in low concentrations, can no longer prevent the polymerisation process of other yet unidentified skin proteins, thereby resulting in the conversion of the secretion to its final glue-like state. Thus, the major defensive value of the skin secretion appears to be mechanical, impeding ingestion through a combination of adhesion and the body inflation typical for some microhylid frogs rather than chemical through antimicrobial activity or toxicity.
Received: 11 April 2013 / Accepted: 19 June 2013 / Published online: 07 July 2013
A third microendemic to the Iwokrama Mountains of central Guyana: a new “cryptic” species of Allobates Zimmerman and Zimmerman, 1988 (Anura: Aromobatidae)Download PDFAbstract
The aromobatid frog Allobates amissibilis sp. nov. is described from a very limited area in the Iwokrama Mountains at elevations between 160 and 950 m, in central Guyana, South America. The new taxon is diagnosed from other Allobates species by morphology, bioacoustics, and genetics, and can be distinguished readily from known congeners by cryptic colouration, small size (16.3–17.8 mm snout-vent length), absence of distinct dorsal pattern in living adult individuals, presence of a distinctly enlarged tubercle on each eyelid, diffuse broad oblique lateral stripe extending from groin to about midbody length, sexually dimorphic throat colouration (pinkish grey, suffused with dark pigment in male, immaculate cream to yellow in female), belly cream to yellow in both sexes, and distinct vocalisation formed by calls of usually 9–12 notes emitted between silent intervals of usually ca. 2–6 s, with a dominant frequency ranging from 5,064 to 5,845 Hz. The new species is the third microendemic reported from the Iwokrama Mountains together with the caecilian Caecilita iwokramae and the lizard Gonatodes timidus. We recommend considering the conservation status of the new species as Data Deficient, and highlight that environmental impact assessments are needed to refine its IUCN threat status.
Received: 14 March 2012 / Accepted: 29 August 2012 / Published online: 11 October 2012
Insights into panicoid inflorescence evolutionDownload PDFAbstract
Inflorescence forms can be described by different combinatorial patterns of meristem fates (indeterminate versus determinate). In theory, the model predicts that any combination is possible. Whether this is true for grasses is unknown. In this paper, the subfamily Panicoideae s.s. (panicoid grasses) was chosen as the model group to investigate this aspect of grass inflorescence evolution. We have studied the inflorescence morphology of 201 species to complement information available in the literature. We have identified the most recurrent inflorescence types and character states among panicoids. Using multivariate approaches, we have indentified correlations among different inflorescence character states. By phylogenetic reconstruction methods we have inferred the patterns of panicoid inflorescence evolution. Our results demonstrate that not all theoretical combinatorial patterns of variation are found in panicoids. The fact that each panicoid lineage has a unique pattern of inflorescence evolution adds an evolutionary component to combinatorial model.
Received: 26 January 2011 / Accepted: 07 June 2012 / Published online: 03 July 2012
Biogeographic patterns in the chromosomal distribution of a satellite DNA in the banded tetra Astyanax fasciatus (Teleostei: Characiformes)Download PDFAbstract
The As-51 satellite DNA is a transposon-like sequence formerly described for arthropods and physically identifiable by fluorescent in situ hybridization. In the present work, we describe the occurrence of this sequence, as well the C-banding and karyotype composition, in populations of the group Astyanax fasciatus from Mogi-Guaçu (Araras-SP), Paranapanema (Angatuba and Pilar do Sul-SP), Ribeira de Iguape (Sete Barras-SP) and Tietê (Indaiatuba and Salesópolis-SP) river basins. The specimens from Sete Barras (10 M + 20SM + 12ST + 6A) and Araras (8 M + 22SM + 12ST + 6A) have 2n = 48 chromosomes. The samples from Angatuba, Pilar do Sul and Indaiatuba presented 2n = 46 chromosomes (12 M + 20SM + 10ST + 4A). The individuals collected in Salesópolis showed three cytotypes, bearing 2n = 46 (12 M + 20SM + 10ST + 4A), 2n = 48 (8 M + 22SM + 12ST + 6A) and 2n = 50 (8 M + 16SM + 14ST + 12A). C-banding revealed large heterochromatic blocks at terminal chromosomal regions in all populations and/or cytotypes. All analyzed populations have conspicuous blocks carrying the As-51 satellite DNA, although the number of chromosomes bearing this repetitive sequence was variable among them. Such differences were not related to the diploid number of individuals, but rather to a biogeographic pattern. Aspects of the karyotype evolution and distribution of this sequence in distinct populations are discussed.
Received: 19 April 2012 / Accepted: 12 September 2012 / Published online: 29 September 2012
The Acoela: on their kind and kinships, especially with nemertodermatids and xenoturbellids (Bilateria incertae sedis)Download PDFAbstract
Acoels are among the simplest worms and therefore have often been pivotal in discussions of the origin of the Bilateria. Initially thought primitive because of their “planula-like” morphology, including their lumenless digestive system, they were subsequently dismissed by many morphologists as a specialized clade of the Platyhelminthes. However, since molecular phylogenies placed them outside the Platyhelminthes and outside all other phyla at the base of the Bilateria, they became the focus of renewed debate and research. We review what is currently known of acoels, including information regarding their morphology, development, systematics, and phylogenetic relationships, and put some of these topics in a historical perspective to show how the application of new methods contributed to the progress in understanding these animals. Taking all available data into consideration, clear-cut conclusions cannot be made; however, in our view it becomes successively clearer that acoelomorphs are a “basal” but “divergent” branch of the Bilateria.
Received: 09 January 2013 / Accepted: 24 April 2013 / Published online: 13 May 2013
The use of compensatory base change analysis of ITS2 as a tool in the phylogeny of Mucorales, illustrated by the Mucor circinelloides complexDownload PDFAbstract
Compensatory base changes (CBCs) in helix II of rDNA ITS2, suggested as a molecular classifier for fungi, were analyzed in Mucor circinelloides and its varieties. Only a few CBCs were found in the complex. Three out of the four accepted formae (f. circinelloides, f. lusitanicus, f. janssenii) did not exhibit CBCs. One CBC was found between strains that form zygospores; consequently, CBC is not always concordant with mating experiments. Strains with two CBC are unable to breed. It is suggested that some strains of the M. circinelloides complex are at the beginning of speciation.
Received: 02 April 2012 / Accepted: 05 June 2012 / Published online: 26 June 2012
Molecules and morphology suggest cryptic species diversity and an overall complex taxonomy of fish scale geckos, genus Geckolepis
The current classification of the Malagasy-Comoroan geckos of the genus Geckolepis recognizes three valid species and is based on morphological differences only. Species allocation of individuals is difficult, mainly because of the insufficiently known degree of variation and the frequent partial loss of the integument in preserved specimens. Here we study Geckolepis specimens from almost their entire known range. We combine molecular and morphological data to estimate species richness in the genus, and to assess the taxonomic validity of the morphological differences proposed. Analyses of mitochondrial (12S, ND4) and nuclear (RAG1, CMOS) gene sequences support three major clades in addition to the morphologically distinct G. polylepis (included for 12S only), and the presence of various divergent lineages within these clades, some occurring in sympatry. Among lineages, the external morphology seems to be comparatively conservative, and differences are faint in many cases. For each major lineage, we summarize the most diagnostic morphological characters that distinguish it from other lineages. The combined molecular and morphological data strongly indicate the presence of highly divergent lineages, three of which are tentatively referred to the names Geckolepis maculata, G. polylepis and G. typica, whereas three other major lineages are considered Confirmed Candidate Species. Among the remaining lineages, differentiation is shallower, and these may qualify for Deep Conspecific Lineages. In conclusion, our analysis provides evidence for an underestimation of species richness in the genus and a complex evolutionary history, not reflected by current Geckolepis species-level taxonomy.
Received: 07 May 2012 / Accepted: 20 August 2012 / Published online: 02 October 2012
Description of Spadella valsalinae sp. nov., a neo-endemic benthic chaetognath from Northern Adriatic Sea (Croatia) with remarks on its morphology, phylogeny and biogeographyDownload PDFAbstract
We describe a new chaetognath species, Spadella valsalinae sp. nov., discovered and collected in the Northern Adriatic Sea (Pula, Croatia). S. valsalinae sp. nov. is a benthic species living at 10–12 m depth attached to the surface of roughly sorted sediment. The cosmopolitan, seagrass-inhabiting species Spadella cephaloptera Busch, 1851 was also recorded in the sampling area. Characters from comparative morphology and molecular phylogeny based on SSU rRNA (18S) sequences support a sister group relationship of S. valsalinae sp. nov. with Spadella lainezi and Spadella ledoyeri. Thus, S. valsalinae sp. nov. represents the first member in the ‘Spadella ledoyeri' complex that is not a troglophilic species. By comparison with the various known European Spadella species, we defined a specific set of morphological characters, such as the number, shape and mutual proportions of the teeth, the lateral fins, the corona ciliata, the seminal vesicles, as well as the presence of ventral adhesive papillae, which is unique for S. valsalinae sp. nov. The biogeography of Spadella members in the Mediterranean Sea and the Eastern Atlantic as well as their phylogenetic relationships are discussed, with the focus on processes of neo-endemism in an epeiric area like, for instance, the Northern Adriatic Sea.
Received: 22 October 2012 / Accepted: 08 January 2013 / Published online: 23 January 2013
A review of the genus Pimpla Fabricius, 1804 (Hymenoptera: Ichneumonidae: Pimplinae) from Vietnam with descriptions of two new speciesDownload PDFAbstract
The ichneumonid wasp genus Pimpla Fabricius, 1804 is reviewed for the first time from Vietnam. Two new species are described: Pimpla lexuanhuei sp. nov. from Phu Tho Province and Pimpla chuyansinensis sp. nov. from Dak Lak Province. Five further species are recorded as new for Vietnam: P. bilineata (Cameron), P. cameronii Dalla Torre, P. ereba Cameron, P. flavipalpis Cameron, and P. laothoe Cameron. Pimpla instigator (Fabricius, 1793), a junior synonym of P. rufipes (Miller, 1759), previously recorded from Vietnam, was re-identified as P. laothoe and therefore is excluded from the ichneumonid fauna of Vietnam. A key to all ten species listed in this paper is also compiled.
Received: 04 February 2013 / Accepted: 06 July 2013 / Published online: 10 August 2013
A multigene phylogeny demonstrates that Tuber aestivum and Tuber uncinatum are conspecificDownload PDFAbstract
For almost 2 centuries it has been disputed whether Tuber aestivum and Tuber uncinatum constitute two different species of truffles. Molecular markers have been applied previously to contribute to resolving this question, coming to different conclusions. In this study, we address this question by analyzing the genetic structure of truffles assigned to either of the two putative species from a geographically broad sampling across Europe. We used an approach involving multigene phylogenies and coalescent analyses of nine regions from five genes. All tests conducted supported the conspecificity of Tuber aestivum and Tuber uncinatum.
Received: 12 December 2011 / Accepted: 20 August 2012 / Published online: 13 September 2012
Genetic differentiation of the African dwarf crocodile Osteolaemus tetraspis Cope, 1861 (Crocodylia: Crocodylidae) and consequences for European zoosDownload PDFAbstract
The endangered African dwarf crocodile Osteolaemus tetraspis is distributed in Central and Western Africa. Conventionally, two subspecies were distinguished: Osteolaemus tetraspis tetraspis and Osteolaemus tetraspis osborni. The taxonomic significance of diagnostic morphological characters is still being discussed and the existence of additional species in the Osteolaemus group remains unclear. Recent molecular studies suggest the existence of three allopatric species in the genus Osteolaemus. These results supported a division of the dwarf crocodile into a Congo Basin form (O. osborni), an Ogooué Basin form (O. tetraspis), and a third separate evolutionary lineage from Western Africa. Several European zoos host African dwarf crocodiles. For reasons of conservation and possible reintroduction, it is important to clarify provenance of these zoo animals. Therefore, we conducted molecular and phylogenetic analyses of three mitochondrial and two nuclear gene sequences with all available samples from European zoos and museums. We also estimated the origin of the zoo animals by comparing sequences of wild animals and museum samples of known provenance. Our study strongly supports three distinct lineages of Osteolaemus as recently postulated, but also reveals a fourth evolutionary lineage. We demonstrate that, of the European zoo animals sampled, only one dwarf crocodile corresponds to the Congo Basin form (O. osborni) whereas the majority of individuals correspond to the three other forms. Four zoo animals belong to the new fourth group; but their provenance is still unresolved. The origin of these animals is probably located in an African region from which no wild animal samples are currently available. Further investigations and sampling of other regions should be completed to clarify the identity of this fourth lineage. We found potential hybrids from European zoological gardens using nuclear DNA sequences. The European Studbook will use these results for further breeding programmes to keep genetically suitable ex-situ populations as reassurance colonies for prospective reintroduction into African countries.
Received: 02 April 2012 / Accepted: 04 March 2013 / Published online: 24 March 2013
Genetic variation within the cosmopolitan aquatic fungus Lignincola laevis (Microascales, Ascomycota)Download PDFAbstract
Recent estimates suggest that there are as many as 10,000 marine fungal species, although the current number stands at just over 500. Previous studies were predominantly surveys of marine fungal diversity on various substrata in Europe, north American and Asia, while little research exists on the possible processes leading to their current distribution. Therefore, this study was initiated to assess the genetic structure and geographical distribution of the cosmopolitan aquatic fungus Lignincola laevis. The internal transcribed spacers and partial 28S region of the rRNA gene clusters, and the partial MCM7 protein gene were sequenced and analysed using maximum parsimony and Bayesian likelihood methods. Three distinct lineages were present in the sampled L. laevis isolates with a mean pairwise distance between the groups >10 %. However, no geographical assemblages could be identified in the phylogeny. The high genetic divergence suggests that Lignincola laevis is a species complex that consists of a group of closely related species with subtle morphological differences. The lack of geographical structure in the sampled isolates of L. laevis may suggest a high dispersal capacity for L. laevis.
Received: 28 May 2012 / Accepted: 05 March 2013 / Published online: 24 March 2013
The oligolecty status of a specialist bee of South American Prosopis (Fabaceae) supported by pollen analysis and floral visitation methodsDownload PDFAbstract
Despite the nest pollen provisions in Western Argentina are composed only of Prosopis, the fact that the ground-nesting bee Eremapis parvula visits several floral hosts suggested that it is a generalist bee species. In the South American Dry Chaco forest, seven nest aggregations of E. parvula were found during three different spring periods. From 34 to 73 species of floral hosts were recorded around each nest aggregation. However, all nest pollen samples were composed of Prosopis pollen alone, as previously found in nests from Western Argentina. Thus, pollen analysis proved that E. parvula is a specialist bee of Prosopis. The “monolecty” and “narrow oligolecty” pollen specialization categories cannot be differentiated using pollen analysis alone. For this reason, a complementary floral visitation method was used. As several Prosopis species have been reported in floral records, the narrow oligolecty category for E. parvula is supported here. Considering that this exomalopsine is a multivoltine bee, and that flowers of some of the more than seven Prosopis species are always available during spring, synchronization between them in rainy periods is highly probable. Thus, it is unlikely that E. parvula has to forage on alternative pollen hosts.
Received: 24 February 2012 / Accepted: 03 November 2012 / Published online: 15 December 2012
The metatrochophore of a deep-sea hydrothermal vent vestimentiferan (Polychaeta: Siboglinidae)Download PDFAbstract
Vestimentiferans (Siboglinidae, Polychaeta) live as juveniles and adults in an obligate mutualistic association with thiotrophic bacteria. Since their development is aposymbiotic, metatrochophores of vestimentiferans from the East Pacific Rise colonizing deep-sea hydrothermal vents are infected with the specific symbiont, develop the trophosome, and reduce their digestive system. To gain insight into the anatomy and ultrastructure and to compare this stage with metatrochophores from other siboglinids, we serial sectioned and reconstructed three specimens using light and transmission electron microscopy. The metatrochophore was composed of a prostomium, a small peristomium, two chaetigers (or two chaetigers and one additional segment without chaetae), and a minute pygidium. A digestive system and an intraepidermal nervous system were developed. Larval organs such as the prototroch, the neurotroch, and an apical organ were present, along with juvenile/adult organs such as tentacles, uncini, pyriform glands, and the anlage of the nephridial organ. We propose that in vestimentiferans, the vestimentum is the head arising from the prostomium, peristomium, and the anterior part of the first chaetiger. In frenulates, in contrast, the head is composed on the one hand of the cephalic lobe arising from the prostomium and on the other of the forepart developing from the peristomium and the anterior part of the first chaetiger. In frenulates the muscular septum between the forepart and trunk develops later than the first two chaetigers. Since this septum has no counterpart in vestimentiferans, the forepart-trunk border of frenulates is not considered homologous with the vestimentum-trunk border in vestimentiferans. The obturacular region in vestimentiferans does not appear to be a body region but rather the head appendages arising from the first chaetiger. In contrast, the tentacles in frenulates are prostomial head appendages. In both taxa, the trunk is the posterior part of the first chaetiger, and the opisthosoma is the following chaetigers and the pygidium. Comparisons with other polychaetes suggest that two larval segments are autapomorphic for the monophyletic Siboglinidae.
Received: 16 June 2012 / Accepted: 13 December 2012 / Published online: 25 January 2013
Evidence from morphological and genetic data confirms that Colossendeis tenera Hilton, 1943 (Arthropoda: Pycnogonida), does not belong to the Colossendeis megalonyx Hoek, 1881 complexDownload PDFAbstract
Within the Pycnogonida, genetic studies have revealed that Colossendeis megalonyx Hoek (Challenger Report, Zoology, 3(X), 1–167, 1881), consists of a complex of several cryptic or overlooked species. Colossendeis megalonyx is a typical Southern Hemisphere species complex distributed primarily on the continental shelves in the Antarctic and Subantarctic. However, a different Colossendeis species with a completely different geographic distribution range, Colossendeis tenera Hilton (Journal of Entomology and Zoology, Pomona College, Claremont, 35(1), 2–4, 1943), was considered a subspecies of Colossendeis megalonyx by Turpaeva (Trudy Instituta Okeanology "P. P. Shirshova", Akademy Nauk SSSR, 103, 230–246, 1975). Colossendeis tenera occurs predominantly along the Pacific Coast of North America from the Bering Sea to central California. Prominent differences between these two currently distinct species are found in body proportions and other characters that were interpreted by Turpaeva as a possible case of pedomorphosis induced by deep-sea conditions. In this study, we tested the hypothesis that Colossendeis tenera belongs to the Colossendeis megalonyx complex by analyzing available and novel sequence data (CO1 and H3) of both Colossendeis megalonyx and Colossendeis tenera as well as a similar, apparently closely related species, Colossendeis angusta Sars (Archiv for Mathematik og Naturvidenskab, 2, 237–271, 1877). We compared morphometric data and SEM of the ovigera of these species. Our results clearly indicate that Colossendeis tenera and Colossendeis angusta are not a part of the Colossendeis megalonyx complex. A sister-group relationship of Colossendeis tenera and Colossendeis angusta is strongly supported, but Colossendeis tenera is not clearly resolved as monophyletic with respect to Colossendeis angusta. This work highlights the need for further examination of the variation found in the tenera-angusta clade. It also gives a first hint of the phylogenetic affinities of species within Colossendeis.
Received: 28 December 2012 / Accepted: 21 May 2013 / Published online: 19 June 2013
3D- microanatomy of the semiterrestrial slug Gascoignella aprica Jensen, 1985—a basal plakobranchacean sacoglossan (Gastropoda, Panpulmonata)Download PDFAbstract
The monophyly of the panpulmonate, usually marine benthic Sacoglossa—and its basal division into shelled Oxynoacea and shell-less Plakobranchacea—is undisputed, but family relationships are in doubt. Of particular interest is the potentially basal plakobranchacean family Platyhedylidae, comprising morphologically aberrant members lacking head tentacles or body appendages. Herein we re-describe the type species of the genus Gascoignella, G. aprica Jensen, 1985, from Hong Kong. Morphological data was generated by three-dimensional reconstruction from serial semi-thin sections using Amira software. Our microanatomical results largely confirm the original description. The anterior digestive system is sacoglossan-like but modified, e.g. the ascus is not demarcated externally and pharyngeal pouches are lacking. The digestive gland is bipartite, with two rami separated by a longitudinal, muscular, median septum, but fused in the rear end. The postpharyngeally situated nerve ring contains fused cerebropleural ganglia; the short visceral loop has three ganglia. Two major cerebral nerves were identified as rhinophoral and labiotentacular nerves, innervating sensory areas on the head velum. Gascoignella aprica is a hermaphrodite with a truly androdiaulic genital system of which some originally ambiguous characters are clarified. Bursa and prostate insert into a fertilization chamber proximal to a sac-like albumen gland and a tubular mucus gland. The cephalic copulatory apparatus contains a penis armed with a short and straight stylet and an accessory gland of unclear function; the presumed mode of sperm transfer is discussed. A well-developed heart and a large H-shaped kidney are present; the nephroduct opens into the intestine. Epidermal glands and body tissues are described for the first time. The presence of a unique longitudinal, median septum is considered diagnostic for Platyhedylidae, multiple further apomorphies are given. Morphological evidence supports the molecular phylogenetic hypothesis that the Platyhedylidae could be a basal non-shelled sacoglossan lineage.
Received: 05 October 2012 / Accepted: 30 March 2013 / Published online: 10 May 2013
Fine-scale population genetic structure in Artemia urmiana (Günther, 1890) based on mtDNA sequences and ISSR genomic fingerprintingDownload PDFAbstract
We investigated the genetic variability and population structure of the halophilic zooplankter Artemia urmiana from 15 different geographical locations of Lake Urmia using nucleotide sequences of COI (mtDNA cytochrome c oxidase subunit I) and genomic fingerprinting by ISSR-PCR (inter-simple sequence repeats). According to sequence data, A. urmiana exhibits a high level of haplotype diversity with a low level of nucleotide diversity. The haplotype spanning network recognized 36 closely related unique haplotypes. ISSR profiles confirmed a substantial amount of genomic diversity with a low level of population structure. No apparent genetic structure was recognized in Lake Urmia but rather a random geographic distribution of genotypes indicating a high degree of panmixia. The population genetic data indicate the possibility of an individual’s relationship, implying that differentiation of individuals is not affected by ecological factors. Therefore, the A. urmiana population from Lake Urmia should be considered as a single management unit for conservation.
Received: 20 November 2012 / Accepted: 22 January 2013 / Published online: 08 February 2013
Quaternary refugia in southwestern Iran: insights from two sympatric moth species (Insecta, Lepidoptera)Download PDFAbstract
Alternating glacial and interglacial periods led to range shifts (contractions and expansions), persistence in distinct glacial refugia and extinction events in various temperate organisms. Today, the integrative analysis of molecular markers and spatial distribution models conducted for multiple taxa allows the detection of phylogeographical patterns, thus reconstructing major biogeographical events in their shared evolutionary history. In this study, the effects of past climate change on the evolutionary history of two sympatric moth species (Gnopharmia colchidaria s.l. and G. kasrunensis) and their host plants (Prunus scoparia and P. fenzliana) were inferred for the largely neglected biodiversity hot spot Iran. We complementarily analyzed the population structure of both moth species (187 specimens, based on COI) in congruence with batched species distribution models (SDMs) for all four taxa and for the times of the Last Glacial Maximum (21 ky BP), 6 ky BP and today. Coincidence of SDMs and the distribution of haplotype lineages indicated a shared refugium for the southwestern Zagros Mountains and potential species-specific refugial areas in the southern Caucasus and the Kope-Dagh Mountains. Both moth species experienced past population expansion.
Received: 22 September 2012 / Accepted: 15 February 2013 / Published online: 09 March 2013
New species of Ophelina (Annelida: Opheliidae: Ophelininae) from northern AustraliaDownload PDFAbstract
Three species of the genus Ophelina are described from northern Australian waters. Ophelina fauveli (Caullery, 1944) is reported for the first time in Australian waters and its description has been updated; the two other species are new to science and are formally described. The main diagnostic characters for the species are based on differences in the pygidial funnel. Ophelina tessellata sp. nov. is distinguished by having a club-shaped funnel with a distinctive tessellated pattern on the ventral edge. Ophelina cyprophilia sp. nov. has a more elongated pygidial funnel and fewer rim cirri. Recognition of these two morphologically similar species was supported by sequences of the cytochrome oxidase I and histone H3 genes.
Received: 29 September 2012 / Accepted: 28 December 2012 / Published online: 09 February 2013
Biogeography, ecology, acoustics and chromosomes of East African Eurycorypha Stål species (Orthoptera, Phaneropterinae) with the description of new speciesDownload PDFAbstract
Although Eurycorypha is the most species-rich Phaneropterinae genus in Africa, little is known about the distribution and the ecology of the species. In this study data on distribution, ecology, song and on chromosomes of some East African species are provided. The nymphs of some species are shown, famous for their ant-like appearance and behaviour. The male of E. punctipennis Chopard and three species of Eurycorypha are newly described. These are E. resonans n. sp. and E. combretoides n. sp. occurring in different habitats on Mount Kilimanjaro, and E. conclusa n. sp from forest habitats along the Tanzanian coast. Bioacoustically, the four recorded species are unusually divers, presenting non-resonant and resonant songs. As four Eurycorypha species occur syntopically on geological young Mount Kilimanjaro, the biogeographical pattern and possible speciation mechanisms in the genus Eurycorypha are discussed in context of the climatical history of eastern Africa.
Received: 29 December 2011 / Accepted: 02 October 2012 / Published online: 06 November 2012
Contrasting phylogenetic patterns of anther smuts (Pucciniomycotina: Microbotryum) reflect phylogenetic patterns of their caryophyllaceous hostsDownload PDFAbstract
Anther smuts in the genus Microbotryum often show very high host specificity toward their caryophyllaceous hosts, but some of the larger host groups such as Dianthus are crucially undersampled for these parasites so that the question of host specificity cannot be answered conclusively. In this study we sequenced the internal transcribed spacer (ITS) region of members of the Microbotryum dianthorum species complex as well as their Dianthus hosts. We compared phylogenetic trees of these parasites including sequences of anther smuts from other Caryophyllaceae, mainly Silene, with phylogenies of Caryophyllaceae that are known to harbor anther smuts. Additionally we tested whether observed patterns in parasites are due to shared ancestry or if geographic separation is a factor that should be taken into consideration in delimitating species. Parasites on Dianthus showed mainly an arbitrary distribution on Dianthus hosts, whereas parasites on other Caryophyllaceae formed well-supported monophyletic clades that corresponded to restricted host groups. The same pattern was observed in the Caryophyllaceae studied: morphologically described Dianthus species did not correspond well with monophyletic clades based on molecular data, whereas other Caryophyllaceae mainly did. We suggest that these different patterns primarily result from different breeding systems and speciation times between different host groups as well as difficulties in species delimitations in the genus Dianthus.
Received: 02 July 2012 / Accepted: 19 September 2012 / Published online: 09 October 2012
Weak divergence among African, Malagasy and Seychellois hinged terrapins (Pelusios castanoides, P. subniger) and evidence for human-mediated oversea dispersalDownload PDFAbstract
Using phylogenetic and haplotype network analyses of 2036 bp of mitochondrial DNA, we compare samples of the two hinged terrapin species Pelusios castanoides and P. subniger from continental Africa, Madagascar and the Seychelles to infer their biogeography. Owing to the long independent history of Madagascar and the Seychelles, the populations from those islands should be deeply divergent from their African conspecifics. Seychellois populations of the two species are currently recognized as Critically Endangered endemic subspecies. However, even though we found within P. subniger evidence for a cryptic species from the Democratic Republic of the Congo, all other samples assigned to this species were undifferentiated. This suggests that Malagasy and Seychellois populations of P. subniger were introduced by humans and that the Seychellois subspecies P. s. parietalis is invalid. This has implications for current conservation strategies for the Critically Endangered Seychellois populations and suggests that measures should rather focus on endemic species. The situation of P. castanoides could be different. Samples from Madagascar and the Seychelles are weakly, but consistently, differentiated from continental African samples, and Malagasy and Seychellois samples are reciprocally monophyletic in maximum likelihood analyses. However, due to a lack of samples from central and northern Mozambique and Tanzania, we cannot exclude that identical continental haplotypes exist there.
Received: 05 December 2012 / Accepted: 27 February 2013 / Published online: 17 March 2013
Nectar production in the pollen flower of Anemone nemorosa in comparison with other Ranunculaceae and Magnolia (Magnoliaceae)Download PDFAbstract
The observation that the flowers of Anemone nemorosa offer nectar to pollinating bee-flies (Bombylius major) prompted this investigation into the site of nectar secretion and nectary tissue. To allow comparison on a broader basis, other nectar-secreting pollen flowers of the Ranunculaceae and Magnolia (Magnoliaceae) were included in the analysis. The contradictory information available on the function of the mouthparts of bee-flies during nectar and pollen feeding motivated us to investigate the proboscis structure in detail by SEM. Our investigations in Anemone nemorosa proved, for the first time, nectar secretion in the genus Anemone s.s. (i.e. other than the Pulsatilla group) and in addition, within the family, a new type of a carpellary nectary. The latter is an epithelial nectary involving the whole epidermis of the ovarian part of the carpel. The nectary of Anemone nemorosa resembles that of Magnolia (e.g. M. stellata), which we re-investigated. In both Anemone nemorosa and Magnolia stellata, nectar production is limited mainly to the female phase of the proterogynous flower. In this way, the attractiveness of the flower is also assured in the non-pollen presenting phase. Especially in Magnolia, with its numerous carpels arranged on a cone-like receptacle, the economic disadvantage of a choricarpous- compared to a coenocarpous-gynoecium is compensated for by nectar secretion by each carpel. When licking up the nectar droplets from the carpel surfaces, contact of the insect's body with each stigma may be achieved.
Received: 16 February 2012 / Accepted: 01 June 2012 / Published online: 21 June 2012
The head anatomy of Epiophlebia superstes (Odonata: Epiophlebiidae)Download PDFAbstract
The relic dragonfly family Epiophlebiidae is recovered as sistergroup of Anisoptera (= Epiprocta) by most molecular and morphological analyses. However, in a recent study it was placed within Anisoptera as sister group of Cordulegastridae. In another study, several affinities to Zygoptera in the morphology of the ovipositor and the egg-laying behaviour were pointed out. Here, we present a detailed study of the outer, as well as the inner, head morphology of Epiophlebia superstes. Compared with the last detailed literature account, three additional mandibular muscles were discovered, as well as additional buccal and pharyngeal muscles. The results are compared with the anatomic features of Zygoptera and Anisoptera. A formal character evaluation focused on head characters confirms the sistergroup relationship of Epiophlebiidae and Anisoptera.
Received: 20 December 2012 / Accepted: 04 March 2013 / Published online: 28 March 2013
The genus Aerotegmina (Orthoptera, Tettigoniidae, Hexacentrinae): chromosomes, morphological relations, phylogeographical patterns and description of a new speciesDownload PDFAbstract
The genus Aerotegmina Hemp is common on East African mountains. Two species are known and a third, A. taitensis n. sp., is described in this paper. A. kilimandjarica Hemp is widespread while A. shengenae Hemp is endemic to the South Pare Mountains and A. taitensis n. sp. is known only from the Taita Hills. Morphologically, and from their song, A. shengenae and A. taitensis n. sp. are closely related. In chromosome number A. kilimandjarica (2n = 33) differs clearly from A. shengenae (2n = 27). Data presented on other flightless Orthoptera suggest that the South Pare Mountains and the Taita Hills, both belonging to the geologically old mountain chain of the Eastern Arc, show a faunistic similarity not shared by any other mountain range in the area. The mechanisms that led to this phylogeographic pattern in flightless Orthoptera in the Eastern Arc Mountains of northern Tanzania and southern Kenya and the inland volcanoes are discussed. A key to the three Aerotegmina species is presented, as well as bioacoustical data of all species compared to the phaneropterine species Euryastes jagoi.
Received: 28 November 2012 / Accepted: 04 April 2013 / Published online: 21 April 2013
Molecular evidence for the origin and evolutionary history of the rare American desert monotypic family SetchellanthaceaeDownload PDFAbstract
Setchellanthus caeruleus, which has disjunct populations in the north of the Chihuahuan Desert and in the Tehuacán-Cuicatlán valley, was selected to understand the evolutionary history of plants in this desert and its southerly relicts. This species constitutes the monotypic family Setchellanthaceae, which forms part of a group of plants that produce mustard-oil glucosides or glucosinolates. Molecular phylogenetic analyses based on DNA plastid sequences of plants of S. caeruleus from both areas, including representative taxa of the order Brassicales, were carried out to estimate the time of origin of the family (based on matK + rcbL) and divergence of populations (based on psbI-K, trnh-psbA, trnL-trnF). In addition, comparative ecological niche modelling was performed to detect if climate variables vary significantly in northern and southern populations. Analyses revealed that Setchellanthaceae is an ancient lineage that originated between 78 and 112 Mya during the mid-late Cretaceous—much earlier than the formation of the Chihuahuan Desert. The molecular data matrix displayed a few indel events as the only differences of plastid DNA sequences between northern and southern populations. It is suggested that due to climate changes in this desert in the Pliocene, populations of Setchellanthus remained in the Sierra de Jimulco and in Cuicatlán, in climatically stable locations. Ecological niche models of northern populations predict niches of southern populations and identity niche tests indicate that there are no differences in their ecological niches.
Received: 19 August 2012 / Accepted: 18 October 2012 / Published online: 14 November 2012
A new species of Gracixalus (Amphibia: Anura: Rhacophoridae) from northern VietnamDownload PDFAbstract
We describe a new species of small tree frog from northern Vietnam based on morphological differences and molecular divergence. Gracixalus waza sp. nov. is distinguishable from its congeners and other small rhacophorid species on the basis of a combination of the following characters: (1) size small (snout-vent length of males 27.1–32.9 mm, of females 37.6 mm); (2) head as wide as or wider than long; (3) vomerine teeth absent; (4) snout rounded and long (16–18 % of the snout-vent length); (5) spines on upper eyelid absent; (6) tibiotarsal projection absent; (7) dorsal skin smooth; (8) dermal fringes on forearm and tarsus absent; (9) dorsal surface of head and body greyish-green to moss-green with dark brown pattern forming an inverse Y marking; and (10) throat and chest with dark marbling. Our molecular data showed that the new species is nested in the same group with Gracixalus jinxiuensis sensu lato.
Received: 22 January 2013 / Accepted: 02 June 2013 / Published online: 27 June 2013
Northern origin and diversification in the central lowlands? – Complex phylogeography and taxonomy of widespread day geckos (Phelsuma) from MadagascarDownload PDFAbstract
Day geckos of the Phelsuma lineata group are widespread in Madagascar and have been historically split into numerous species and subspecies based almost exclusively on differences in coloration and body size. We apply phylogenetic and phylogeographic methods to examine the biogeography and taxonomy of these lizards, including explicit tests of various biogeographic predictions and based on a molecular data set covering much of the distribution ranges of all species and subspecies of P. lineata, P. dorsivittata, P. comorensis, P. hoeschi, P. kely, and P. pusilla in Madagascar (and the Comoros archipelago for P. comorensis). Sequences of the mitochondrial 16S rRNA and the nuclear RAG-1 gene fragment were determined from 376 samples, and a multigene mtDNA phylogeny of the species group was constructed for the main phylogroups identified in the 16S haplotype network. We used the 16S sequences to estimate the geographic location of the ancestor of each major mtDNA clade and to infer their demographic history using a variety of statistical tools. Our phylogeny separates the taxa analyzed into two well-supported major subclades mainly occurring in the north respectively east of the island. Mismatch distribution of samples together with rejection of neutrality, the results of Bayesian Skyline Plots analysis, and a star-like network suggests a recent demographic expansion for the P. l. lineata lineage into the eastern lowlands, while the highland (P. l. elanthana) and northern clades (P. dorsivittata and P. l. punctulata) show signatures of rather stable populations. A major genetic discontinuity observed coincided with a northern lowland stretch that separates mid-altitude rainforests in the north from those in the center and south. Our analysis points to numerous unsolved taxonomic problems in this group of geckos, especially in the small-sized taxa (P. hoeschi, P. kely, P. pusilla), and provides a basis for a future comprehensive taxonomic revision, which will require integrative analysis of molecular, morphological and chromatic data as well as careful examination of type specimens.
Received: 23 February 2012 / Accepted: 30 April 2012 / Published online: 12 June 2012
Insemination by a kiss? Interactive 3D-microanatomy, biology and systematics of the mesopsammic cephalaspidean sea slug Pluscula cuica Marcus, 1953 from Brazil (Gastropoda: Euopisthobranchia: Philinoglossidae)Download PDFAbstract
Increasing molecular evidence suggests that the phylogeny of euthyneuran gastropods differs greatly from centenary textbook concepts. The presence, homology and evolution of characters in major subgroups thus need to be reinvestigated. Traditionally basal opisthobranch Cephalaspidea (“head-shield snails and slugs”) were pruned to a new taxon concept, with benthic euopisthobranch and tentacle-bearing cephalaspidean lineages basal to burrowing, head-shield bearing philinoidean species. Among the latter, mesopsammic “microslug” lineages evolved at least twice. Herein we explore in 3D microanatomical detail the putatively basal philinoglossan Pluscula cuica (Marcus, Boletim da Faculdade de Filosofia, Ciências e Letras. Universidade de São Paulo 164:165–203, 1953a) from its type locality in Brazil. The species possesses several “accessory” ganglia and a reduced posterior mantle cavity that retains some putative shell-building tissue and an osphradium. The hermaphroditic, monaulic genital system opens in a posterior position; it retains a bursa copulatrix but lacks a distinct receptaculum seminis. Autosperm is transferred to the cephalic copulatory organ via an external sperm groove, not through the hemocoel, as suggested in the original description. The penis opens through the oral tube, sperm is transferred by a “kiss”. A conspicuous yellow gland is discussed as a modified Blochmann’s gland. Retaining several putative symplesiomorphies with philinoids, Pluscula is discussed as the most basal offshoot in meiofaunal Philinoglossidae. However, the supposed “primitiveness” of the fused rather than separate cerebropleural ganglia and the triganglionate rather than pentaganglionate visceral nerve cord was based on misobservations. Higher categories such as Philinoglossacea for Philinoglossidae, and a separate family Plusculidae for P. cuica are no longer warranted. Inner cephalaspidean relationships and a scenario of more or less successive philinoglossid adaptation to meiofaunal environments should be investigated by molecular studies with more comprehensive taxon sampling.
Received: 12 May 2011 / Accepted: 07 June 2012 / Published online: 08 July 2012
A RAPD study of the Sarcostemma group of Cynanchum (Apocynaceae-Asclepiadoideae-Asclepiadeae)Download PDFAbstract
One hundred and thirty-seven accessions of Cynanchum viminale and its relatives, formerly known as Sarcostemma, were studied using randomly amplified polymorphic DNA (RAPD). A fingerprinting technique was used because sequencing had failed to differentiate between morphologically separable groups. Chromosome counts were conducted to establish the ploidy level of the accessions. The banding patterns resulting from RAPD analysis were evaluated with Canonical Analysis of Principal Coordinates, Permanova and neighbour-joining. A strong geographic component was found in the structure of the group. Taxa considered species or subspecies based on morphology often formed coherent groups. The data are interpreted to reflect at least two cycles of diversification: the first one from Madagascar and the second one most likely from the East African–Arabian region, reaching Madagascar again. In mainland Africa, polyploidisation has occurred several times.
Received: 01 August 2012 / Accepted: 17 December 2012 / Published online: 20 January 2013
Nematode succession at deep-sea hydrothermal vents after a recent volcanic eruption with the description of two dominant speciesDownload PDFAbstract
Nematodes are very common in the deep sea and are an important component of deep-sea hydrothermal vent communities. In early 2006, the eruption of the underwater volcano at 9°50’N East Pacific Rise wiped out almost the entire faunal communities of the area. This provided us with the opportunity to study nematode primary succession at vents as well as on adjacent seafloor basalt. Nematode abundance and richness were extremely low at all studied sites in late 2006 and 2007, and increased only slightly in 2009. Interestingly, the most abundant species during early succession were also prominent in this area prior to the eruption. Our results show that nematodes are extremely influenced by volcanic eruptions and need a long period of time to colonize the lava-flooded area in greater numbers and richness. We hypothesize that low food availability on the young bare basalt and harsh environmental conditions at early succession vent sites might hinder a more successful nematode establishment. In addition to the newly established active vent sites we also studied an inactive vent site that was not directly hit by the eruption but whose vent fluid had ceased after the eruption. At this inactive and older vent, diversity was also relatively low but was higher than at the younger, newly established sites. In addition to the ecological analyses, we here describe the two most abundant species found at inactive vents, namely Neochromadora aff. poecilosoma De Mann 1893 and Linhomoeus caudipapillosus sp. n.
Published online: 07 November 2013
Prof. Dr. Peter AxDownload PDF
Received: 29 September 2012 / Accepted: 25 January 2013 / Published online: 19 February 2013
Phylogeographic patterns of genetic diversity in the common spadefoot toad, Pelobates fuscus (Anura: Pelobatidae), reveals evolutionary history, postglacial range expansion and secondary contactDownload PDFAbstract
Based on allozyme variation of 410 newly collected individuals from 52 localities, we reconstructed range-wide phylogeography of the widespread Western Palearctic anuran, Pelobates fuscus. To study genetic diversity, evolutionary history, postglacial range expansion and secondary contact zones, we used a multidisciplinary approach combining information from various genetic analyses and ecological niche modeling. We confirmed the presence of two main groups in P. fuscus, initially revealed by genome size variation. Pelobates f. vespertinus presents a monomorphic group, but two main groups can be identified in P. f. fuscus: an East European and a West European group. We suggest the existence of at least four different Last Glacial refugia for P. fuscus: (1) the area between the Caspian and Azov Seas as the origin for the expansion of P. f. vespertinus; (2) the northwestern part of the Black Sea area for the East European P. f. fuscus; (3) the southwestern part of the Pannonian Plain and (4) the Po Plain for the West European P. f. fuscus. The routes of postglacial range expansions from the refugia are discussed. We newly identified a hybrid zone between P. f. fuscus and P. f. vespertinus. The width of this zone is about 12.5 km. In light of these findings, the two subspecies of P. fuscus constitute distinct evolutionary lineages and merit recognition as separate species. Our data do not provide support for the validity of P.f. insubricus. We therefore propose to synonymize this subspecies with P. f. fuscus.
Received: 16 October 2012 / Accepted: 02 May 2013 / Published online: 26 June 2013
Revisiting Amazonian phylogeography: insights into diversification hypotheses and novel perspectivesDownload PDFAbstract
The Amazon Basin harbors one of the richest biotas on Earth, such that a number of diversification hypotheses have been formulated to explain patterns of Amazonian biodiversity and biogeography. For nearly two decades, phylogeographic approaches have been applied to better understand the underlying causes of genetic differentiation and geographic structure among Amazonian organisms. Although this research program has made progress in elucidating several aspects of species diversification in the region, recent methodological and theoretical developments in the discipline of phylogeography will provide new perspectives through more robust hypothesis testing. Herein, we outline central aspects of Amazonian geology and landscape evolution as well as climate and vegetation dynamics through the Neogene and Quaternary to contextualize the historical settings considered by major hypotheses of diversification. We address each of these hypotheses by reviewing key phylogeographic papers and by expanding their respective predictions. We also propose future directions for devising and testing hypotheses. Specifically, combining the exploratory power of phylogeography with the statistical rigor of coalescent methods will greatly expand analytical inferences on the evolutionary history of Amazonian biota. Incorporation of non-genetic data from Earth science disciplines into the phylogeographic approach is key to a better understanding of the influence of climatic and geophysical events on patterns of Amazonian biodiversity and biogeography. In addition, achieving such an integrative enterprise must involve overcoming issues such as limited geographic and taxonomic sampling. These future challenges likely will be accomplished by a combination of extensive collaborative research and incentives for conducting basic inventories.
Received: 01 April 2011 / Accepted: 07 May 2012 / Published online: 05 June 2012
Divergence time estimation in Cichorieae (Asteraceae) using a fossil-calibrated relaxed molecular clockDownload PDFAbstract
Knowing the age of lineages is key to understanding their biogeographic history. We aimed to provide the best estimate of the age of Cichorieae and its subtribes based on available fossil evidence and DNA sequences and to interpret their biogeography in the light of Earth history. With more than 1,550 species, the chicory tribe (Cichorieae, Asteraceae) is distributed predominantly in the northern Hemisphere, with centres of distribution in the Mediterranean region, central Asia, and SW North America. Recently, a new phylogenetic hypothesis of Cichorieae based on ITS sequences has been established, shedding new light on phylogenetic relationships within the tribe, which had not been detected so far. Cichorieae possess echinolophate pollen grains, on the surface of which cavities (lacunae) are separated by ridges. These lacunae and ridges show patterns characteristic of certain groups within Cichorieae. Among the fossil record of echinolophate pollen, the Cichorium intybus-type is the most frequent and also the oldest type (22 to 28.4 million years old). By using an uncorrelated relaxed molecular clock approach, the Cichorieae phylogenetic tree was calibrated with this fossil find. According to the analysis, the tribe originated no later than Oligocene. The species-rich core group originated no later than Late Oligocene or Early Miocene and its subtribes diversified no later than Middle/Late Miocene or Early Pliocene—an eventful period of changing geological setting and climate in the Mediterranean region and Eurasia. The first dispersal from Eurasia to North America, which resulted in the radiation of genera and species in North America (subtribe Microseridinae), also occurred no later than Middle or Late Miocene, suggesting the Bering land bridge as the route of dispersal.
Received: 20 July 2012 / Accepted: 03 January 2013 / Published online: 26 January 2013
Review of Atlantoscia Ferrara & Taiti, 1981 (Crustacea: Isopoda: Oniscidea: Philosciidae) with new records and new speciesDownload PDFAbstract
The neotropical genus Atlantoscia Ferrara & Taiti, 1981 includes three species, A. floridana Van Name, 1940, occurring in coastal regions of Florida (USA), Brazil, Argentina, and Ascension and Saint Helena islands, A. rubromarginata Araujo & Leistikow, 1999 and A. petronioi Campos-Filho, Contreira and Lopes-Leitzke, 2012 from Brazil. Two new species from Brazil are here described, one from the state of Bahia and one from the state of São Paulo. All the new species have respiratory areas on pleopods 1–5 exopods. The specimens were collected in areas of Atlantic Forest and in cocoa (Theobroma cacao) plantations. New records of A. floridana and A. rubromarginata and distribution maps are presented.
Received: 29 February 2012 / Accepted: 14 June 2012 / Published online: 01 August 2012
Jaw musculature during the dawn of turtle evolutionDownload PDFAbstract
Using a new approach to study muscle anatomy in vertebrates, the fully differentiated jaw musculature of 42 turtle species was studied and character mappings were performed. Soft tissue arrangements were correlated to the temporal openings (emarginations) of the skull and the trochlearis system of the jaw apparatus among turtle taxa. When compared to the cranial anatomy of stem Testudines, most characters detected as diagnostic of particular extant groups have to be considered as being evolved first within Testudines. Hence, jaw muscle anatomy of extant turtles is difficult to compare to that of other reptilian taxa. Moreover, the high number of apomorphic character changes speaks for a divergating turtle and saurian morphotype of jaw musculature, which could indicate either a position of turtles outside of Sauria or a highly derived, undetectable origin within that group. In general, a low direct correlation of most soft and hard tissue characters was detected. This finding could imply that both character complexes are more integrated to each other driven by functional morphology; i.e., the composition of muscle fibre types. That condition highlights the difficulty in using gross anatomy of jaw muscle characters to interpret temporal bone arrangements among amniotes in general.
Received: 04 July 2012 / Accepted: 13 December 2012 / Published online: 24 January 2013
Morphology, microanatomy and sequence data of Sclerolinum contortum (Siboglindae, Annelida) of the Gulf of MexicoDownload PDFAbstract
Sclerolinum is a small genus of Siboglinidae (Annelida) living in an obligate mutualistic association with thiotrophic bacteria as adults. Its taxonomic position, based on morphology, has been controversial; however, molecular data point to a sister taxa relationship with vestimentiferans. 16S rRNA gene sequencing and comparative morphology revealed that the studied population from deep-sea hydrocarbon seeps of the Gulf of Mexico belongs to Sclerolinum contortum known from the Arctic Sea. Since no anatomical and microanatomical studies have been published yet, we conducted such a study on S. contortum using serial sectioning and light and transmission electron microscopy. We show that the Sclerolinum body, divided into a head, trunk, and opisthosoma, is very similar to that of the vestimentiferans, and therefore we propose that the body regions are homologous in both taxa.
Received: 04 June 2012 / Accepted: 15 November 2012 / Published online: 09 December 2012
Mitochondrial genomes of the genus Ephydatia Lamouroux, 1816: can palindromic elements be used in species-level studies?Download PDFAbstract
Poriferan mitochondrial DNA (mtDNA), especially large intergenic regions, is a target for the insertion of repetitive hairpin-forming elements. These elements are responsible for the large mt genome size differences observed even among closely related sponge taxa. In this study, we present the new, nearly complete, mt genome sequence of Ephydatia fluviatilis and compare it with previously published mt genomes of freshwater sponges. Special emphasis was placed on comparison with the closely related species Ephydatia muelleri, thereby comparing the only two species of the genus Ephydatia on the western Balkan Peninsula. In particular, we analyzed repetitive palindromic elements within the mitochondrial intergenic regions. The genomic distribution of these repetitive elements was analyzed and their potential role in the evolution of mt genomes discussed. We show here that palindromic elements are widespread through the whole mt genome, including the protein coding genes, thus introducing genetic variability into mt genomes.
Received: 17 August 2012 / Accepted: 04 February 2013 / Published online: 28 February 2013
A centipede nymph in Baltic amber and a new approach to document amber fossilsDownload PDFAbstract
The fossil record and especially examples of fossilized ontogeny have been described for many major arthropod taxa. However, little is yet known about ontogeny in fossil representatives of Myriapoda. Traditionally, taxonomy has focused on adult stages, and tends to “overlook” non-adults. Assigning an early stage to a specific species would demand having “bridging” juvenile stages. Additionally, as shown for other fossil arthropods, juvenile stages of a given species could have been recognized as separate species in the past. In this context, palaeo-evo-devo links evolutionary developmental knowledge with paleontological evidence. We report a nymphal lithobiomorph centipede from Baltic amber. The specimen was documented under cross-polarized light combined with image stacking. Stereo images were created based on these image stacks. Assessable characters are described and compared with data on extant lithobiomorph taxa. We conclude that the nymph (or larva) described here can be assigned to Lithobiidae and probably represents the fourth post-embryonic stadium. Findings such as that described here are still rare and detailed descriptions are not usually provided. The accessible data therefore represent an important example of fossilized ontogeny for centipedes.
Received: 25 September 2012 / Accepted: 21 May 2013 / Published online: 17 June 2013
Spatial pattern of intraspecific mitochondrial diversity in the Northern Carpathian endemic spring snail, Bythinella pannonica (Frauenfeld, 1865) (Gastropoda: Hydrobiidae)Download PDFAbstract
Bythinella is a species-rich genus of spring-snails, having a wide range in Europe and Asia Minor. The genus contains several endemic species with narrow ranges, creating interest from a conservation perspective as well as their use as a model for research into biogeographical patterns and evolutionary development. Most of the species of the genus Bythinella are difficult to distinguish by traditional methods due to their similar shell morphology. In previous studies, molecular approaches often came to conclusions that contradicted those from a morphology-based approach, hence the classification of species of Bythinella has been in dispute. Bythinella pannonica has clearly distinct shell morphological features, and consequently is one of the few species of undisputed taxonomic status within this genus. As an important step towards clarifying the systematics of this genus, we have attempted to describe the structure and spatial pattern of diversity of the mitochondrial COI marker within this species, in the hope of applying these findings generally to the whole genus. Molecular results support the monophyly of B. pannonica within the genus. The largest pairwise intraspecific COI sequence difference was almost 5 %, much larger than the value of 1.5 % previously proposed as a barcoding threshold for delimitation of Bythinella species. This finding suggests that incautious application of barcoding might lead to incorrect taxonomic conclusions. Within B. pannonica there are two deeply divergent intraspecific clades, the spatial distribution of which has been shaped by fragmentation, as well as by short and long distance dispersal events. These two clades have not been found syntopically but, as a peculiar feature of this taxon, they are able to persist in nearby habitats. We have demonstrated that the patchy distribution of suitable habitats and the restricted, but non-zero gene flow amongst the populations might play a key role in maintenance of the observed genetic structure of this species.
Received: 16 February 2012 / Accepted: 14 June 2012 / Published online: 14 July 2012
Conservation genetics and phylogeography of the poorly known Middle Eastern terrapin Mauremys caspica (Testudines: Geoemydidae)Download PDFAbstract
The West Asian stripe-necked terrapin Mauremys caspica is widespread throughout the Middle East—a region for which only few phylogeographic studies are available. Due to landscape alteration, pollution and intensification of water management, M. caspica is increasingly threatened. However, genetic diversity among and within populations is poorly known, impeding the identification of management units. Using a nearly rangewide sampling, we analyzed 14 microsatellite loci and mtDNA sequences in order to gain insight into the population structure and history of M. caspica. In agreement with a previous study, we found two clusters of mitochondrial haplotypes, with one cluster distributed in the east and the other in the west of the range. However, our microsatellite data suggested a more pronounced geographical structuring. When null alleles were coded as recessive with structure 2.3.2, three clusters were revealed, with one cluster matching roughly the range of the western mitochondrial cluster, and the composite ranges of the two other microsatellite clusters correspond to the distribution of the eastern mitochondrial cluster. Naïve structure analyses without correction for null alleles were congruent with respect to the two eastern microsatellite clusters, but subdivided the western cluster into two units, with an additional geographical divide corresponding to the ‘Anatolian diagonal’—a well-known high mountain barrier impeding exchange between western and eastern taxa. In naïve analyses, the westernmost microsatellite cluster (from Central Anatolia) is quite isolated from the others, and its distinctness is also supported by fixation indices resembling the values among the other three clusters. One of the two eastern clusters is distributed in the Caucasus region plus Iran, and terrapins from Saudi Arabia and Bahrain constitute the second eastern cluster, supporting the view that these endangered populations are native. Coalescent-based analyses of our microsatellite data reveal for all four clusters bottlenecks 4,000–20,000 years ago, suggesting that climatic fluctuations of the Late Pleistocene and Holocene played an important role in shaping current genetic diversity. We propose that each of the four identified clusters, including the Central Anatolian one, should be treated as a distinct management unit. The presence of non-native terrapins in the animal trade of Bahrain highlights the danger of genetic pollution of the endangered Arabian populations. Further sampling is needed to elucidate the situation in southern and central Iran and Iraq. Our results confirm that genetic data do not support the validity of any of the three morphologically defined subspecies of M. caspica, and we propose that their usage be abandoned.
Received: 07 July 2012 / Accepted: 27 November 2012 / Published online: 28 December 2012
Morphological and genetic analyses of xeniid soft coral diversity (Octocorallia; Alcyonacea)Download PDFAbstract
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.
Received: 26 October 2012 / Accepted: 07 April 2013 / Published online: 16 May 2013
Reproductive strategy of two deep-sea scalpellid barnacles (Crustacea: Cirripedia: Thoracica) associated with decapods and pycnogonids and the first description of a penis in scalpellid dwarf malesDownload PDFAbstract
We investigated the sexual system in two pedunculate barnacles of the family Scalpellidae. Both inhabit deep water and are attached to mobile arthropod hosts. Verum brachiumcancri was attached to the majid crab Rochinia hertwigi, and Weltnerium nymphocola to the pycnogonidan sea spider Boreonymphon rubrum. Both barnacles have separate sexes and females almost always carry two dwarf males that are almost fully embedded in a pair of symmetrically situated receptacles inside the rim of the mantle cavity. The dwarf males of V. brachiumcancri have a complex penile structure extending into the female mantle cavity. This is the first time a copulatory structure has been described in detail for a dwarf male of a scalpellid barnacle. Both species lack free nauplii and their larvae are released as cyprids; the brood size is small. This is probably an adaptation for settling close to the parent population. We compare reproductive strategies among scalpellids and suggest that the present males are highly specialized and that the females are allocating resources to few offspring.
Received: 07 October 2012 / Accepted: 13 April 2013 / Published online: 04 May 2013
The ontogeny of the lower reproductive tract of the landsnail Helix aspersa (Gastropoda: Mollusca)Download PDFAbstract
We provide a size-based ontogenetic sequence of the development and differentiation of the lower reproductive tract of the heterobranch gastropod Helix aspersa (Müller 1774). Twelve development stages distributed among nine size classes were recognized based on readily visible changes in morphology and changes in tissue density. Geometric morphometrics was used to calculate the deformation between stages as represented by thin-plate spline bending energies. The developmental stages and sequence of developmental events are also compared to previously published scenarios for the evolution of stylommatophoran and other pulmonate reproductive tracts. These comparisons suggest that heterochronies, which include both acceleration and retardation, are operating in the morphological evolution of the pulmonate lower reproductive tract. This supports previous observations that largest number of developmental changes coincides with the transition to sexual maturity, which is also seen in the exponential curve of bending energies we observed in Helix aspersa. The belated organogenesis makes the ontogeny of the complex hermaphroditic reproductive system of pulmonates readily observable in size-friendly juveniles. This observation, coupled with the ease of raising individuals in the laboratory, recommends Helix aspersa as a potential model laboratory system for investigating molluscan evolutionary development.