Received: 22 October 2014 / Accepted: 13 February 2015 / Published online: 25 February 2015
Fossil Monotomidae (Coleoptera: Polyphaga) from Laurasian Cretaceous amberDownload PDFAbstract
Three new species of root-eating beetle (Coleoptera: Monotomidae) in Cretaceous amber from Spain (Albian) and Myanmar (Cenomanian) are described. Rhizophtoma longus sp. nov. is a Spanish monotomid of the tribe Rhizophtomini, previously only known from Lebanese amber (Aptian). The Cretakarenniini tribe nov. is created to include the new species Cretakarenni birmanicus gen. et sp. nov., from Myanmar, and Cretakarenni hispanicus gen. et sp. nov., from Spain. These three new species, together with the previous fossil species known in this family, have a controversial set of characters that makes it extremely difficult to place them in any other extant group of Monotomidae. Fossil monotomids are not numerous, despite their early diverging placement among the cucujoid clade. An updated list of monotomid fossils is provided. The need to classify the new taxa and compare them with extant and extinct groups of Monotomidae is solved using a key for the subfamilies and tribes.
Received: 02 October 2014 / Accepted: 14 January 2015 / Published online: 21 January 2015
A new Dominican amber fossil of the derived fern genus Pleopeltis confirms generic stasis in the epiphytic fern diversity of the West IndiesDownload PDFAbstract
One of the grand objectives in the integration of fossils and phylogenetics is to obtain support for macroecological and macroevolutionary hypotheses. Here, we provide new evidence from Dominican amber fossils, which supports a likely stasis in the generic composition of epiphytic plant communities in the West Indies for at least 16 million years. The proposed hypothesis is based on the discovery of the first fossil of the Neotropical fern genus Pleopeltis. The relationships of this specimen to extant genera are studied using a dated phylogenetic framework to reconstruct the evolution of the characters preserved in the fossil, as well as by exploring the phylomorphospace of Pleopeltis. The fossil corroborates divergence time estimates obtained independently and also suggests the conservation of the generic composition of epiphytic communities. We discovered evidence for conserved morphotypes in the genus Pleopeltis occurring from the mid-Miocene to the present. The innovative use of phylomorphospace reconstruction provided crucial information about the affinities of the fossil. Rather than relying on reconstructing the evolution of single characters, this analysis integrates the evolution of all informative characters observed to evaluate relationships of the fossilized morphotype to extant morphotypes.
Received: 10 September 2014 / Accepted: 05 March 2015 / Published online: 26 March 2015
New cranial material of the earliest filter feeding flamingo Harrisonavis croizeti (Aves, Phoenicopteridae) informs the evolution of the highly specialized filter feeding apparatusDownload PDFAbstract
The Oligo-Miocene flamingo Harrisonavis croizeti represents an intermediate form between the highly specialized extant flamingo cranial morphology and the more generalized ancestral phoenicopteriform one, characterized by the extinct taxon Palaelodus. However, the original description of H. croizeti lacked detail and the lectotypic skull was lost; thus, it is not known how the ancestral phoenicopterid cranial morphology differed from that of recent forms. Here, we describe new cranial material from Oligo-Miocene deposits of France, including a mostly complete skull with an articulated upper bill, a disarticulated upper bill, and pieces of lower bill. We assign this material to H. croizeti and compare it to all previously reported fossil flamingo cranial material as well as to all six living species. We also use 3D computed tomographic data to reconstruct the skull of H. croizeti in three dimensions. The skull and bill of H. croizeti are similar to those of living species, although they display less specialized filter feeding traits, including a straighter bill with less surface area for filtration lamellae and points of articulation with the lower bill which are less developed. The less specialized form of H. croizeti suggests the extant Phoenicopterus retains a skull morphology more similar to the ancestral condition of crown group flamingos, and the extant Phoenicoparrus form is more derived.
Received: 20 August 2014 / Accepted: 16 October 2014 / Published online: 31 October 2014
Flexibility is everything: prey capture throughout the seasonal habitat switches in the smooth newt Lissotriton vulgaris
Transitions between aquatic and terrestrial habitats are significant steps in vertebrate evolution. Due to the different biophysical demands on the whole organism in water and air, such transitions require major changes of many physiological functions, including feeding. Accordingly, the capability to modulate the pre-programmed chain of prey-capture movements might be essential to maintain performance in a new environment. Newts are of special interest in this regard as they show a multiphasic lifestyle where adults change seasonally between an aquatic and a terrestrial stage. For instance, the Alpine newt is capable of using tongue prehension to feed on land only when in the terrestrial stage, but still manages to suction feed if immersed whilst in terrestrial stage. During the aquatic stage, terrestrial feeding always involved grasping prey by the jaws. Here, we show that this seasonal shift in feeding behavior is also present in a species with a shorter terrestrial stage, the smooth newt Lissotriton vulgaris. Behavioral variability increases when animals change from aquatic to terrestrial strikes in the aquatic stage, but prey-capture movements seem to be generally well-coordinated across the feeding modes. Only suction feeding in the terrestrial stage was seldom performed and appeared uncoordinated. Our results indicate that newts exhibit a high degree of seasonal flexibility of the prey-capture behavior. The similarity between movement patterns of suction feeding and terrestrial feeding suggests that only relatively subtle neuromotoric adjustments to the ancestral, suction-feeding motor program are required to successfully feed in the new environment.
Received: 14 July 2014 / Accepted: 05 December 2014 / Published online: 29 January 2015
Focus on the details: morphological evidence supports new cryptic land flatworm (Platyhelminthes) species revealed with moleculesDownload PDFAbstract
We found numerous dull brown land planarians of the subfamily Geoplaninae within native rainforests and in nearby man-disturbed habitats in Southeastern and South Brazil. Their external and internal morphology are similar to those of Obama ladislavii (Von Graff, 1899), with the exception of the luminous green dorsum of this species, from which a brownish-green variation is also known. Since morphological features commonly used to delimit geoplaninid species failed to distinguish them, we used coalescent and Bayesian-based molecular methods (GMYC, BPP). These methods indicated that we were actually dealing with three species, the greenish O. ladislavii, and two brownish, cryptic species. A meticulous morphological study of the specimens, including type material of O. ladislavii, allowed us to ascertain diagnostic features for each of the species, for which we also propose a molecular diagnosis. This integrative taxonomic study demonstrates the utility of molecular tools to weigh minor morphological features and thus to reveal otherwise cryptic species.
Received: 24 October 2013 / Accepted: 02 October 2014 / Published online: 31 October 2014
Recovering the evolutionary history of Africa’s most diverse viper genus: morphological and molecular phylogeny of Bitis (Reptilia: Squamata: Viperidae)Download PDFAbstract
Assessing evolutionary relationships among wide-ranging species can be particularly beneficial to our understanding of speciation patterns and biogeography of taxa, with broad implications for conservation and applications for human health. Integrative phylogenetic analyses that incorporate multiple independent datasets (e.g., DNA, protein, phenotype) can resolve many problematic issues in systematics such as cryptic diversity and incongruence between datasets. Vipers in the genus Bitis are widely distributed throughout much of sub-Saharan Africa, filling a variety of ecological niches and presenting an important public health problem. However, evolutionary relationships among this medically and ecologically important genus have not been fully resolved due to inadequate taxon sampling and lack of informative characters. Here, we conduct the first phylogenetic study incorporating complete sampling of known species within the genus Bitis. Using morphological, molecular, and combined approaches under multiple criteria, we recovered many of the species groups detected by previous investigators, further validating four currently recognized subgenera. Bitis arietans and Bitis worthingtoni appear to be early-diverging, monotypic lineages, while the “big Bitis” group and the small southern African species form distinct clades. Although our study provides additional information regarding the interspecific relationships within Bitis, the placement of Bitis albanica, Bitis heraldica, and Bitis inornata remains problematic. This study enhances our understanding of the evolutionary history of species within the genus Bitis incorporating a combined evidence approach to phylogenetics.
Received: 29 September 2014 / Accepted: 23 February 2015 / Published online: 22 March 2015
New Paramecium (Ciliophora, Oligohymenophorea) congeners shape our view on its biodiversityDownload PDFAbstract
Paramecium is one of the best known and most intensely studied ciliate genera. It currently comprises 18 morphospecies including the P. aurelia complex of 15 sibling species. Here, we describe the new morphospecies Paramecium buetschlii sp. nov. from a freshwater pool in Norway, featuring unusual combinations of morphological characters and a high genetic diversity relative to other congeners. Three further investigated Paramecium spp. from Germany, Hungary, and Brazil are treated as cryptic species, because they are difficult to discriminate from other members of the genus relying on morphological criteria only. However, DNA-based taxonomic markers (18S-rDNA and mitochondrial COI) clearly indicate they are separate species. Due to the lack of an appropriate systematic term within the International Code of Zoological Nomenclature for distinguishing cryptic from valid biological species, we propose the provisional status Eucandidatus as a component of the taxonomic name when describing new but cryptic eukaryotes. Based on our data, we postulate that even within Europe there is a higher biodiversity within this common ciliate group that is heavily used in the classroom. By uncovering potentially distinct species that have been classified under the same species names, our molecular analyses further suggest a higher current stock diversity in Paramecium than previously thought. We also would like to emphasize that under-sampling is another major issue in estimating protist diversity. Future large-scale studies based on extensive sampling not only in exotic and remote regions, but also in less frequently sampled areas, will therefore likely improve our understanding of species richness and diversity.
Received: 09 September 2014 / Accepted: 09 March 2015 / Published online: 26 March 2015
Niche overlap and host specificity in parasitic Maculinea butterflies (Lepidoptera: Lycaenidae) as a measure for potential extinction risks under climate changeDownload PDFAbstract
Species depending on specific biotic interactions are particularly threatened by environmental changes. Therefore, host dependency in species living in parasitic relationships is acknowledged as a crucial factor increasing climatic susceptibility and species decline. In Maculinea butterflies and Myrmica ants, a complex form of social parasitism brings the butterflies into dependency of some few associated ant species for reproductive success. We evaluated to what extent these relations can be attributed to similarity in their climatic niches and whether alterations in niche overlap might foster the climatic susceptibility in Maculinea butterflies under future climate change. We show that the niches of ants and butterflies differ significantly more than expected at random corresponding to the observed flexibility in host exploitation. Moreover, a generally low degree of niche overlap and similar niche overlap scores between main and secondary host associations argue for a low host specificity of Maculinea butterflies. Pronounced range shifts and habitat retractions in all species will result in severe spatial limitations of Maculinea species by the presence of their hosts. No tightening in any of the host-parasite associations was detected under the pressure of range restrictions. Niche overlap scores remain comparably low in future scenarios and call for the possibility of extensive host shifts between all related species. Therefore, the absence of niche constraints might enable the parasites to extensively shift among hosts to allow the co-occurrence of several Maculinea species, in principle using the same host, and to maintain viable populations under the pressure of limited distributions and changing environments.
Received: 27 April 2015 / Accepted: 04 June 2015 / Published online: 14 June 2015
The phylogenetic position of Neogosseidae (Gastrotricha: Chaetonotida) and the origin of planktonic GastrotrichaDownload PDFAbstract
Planktonic forms of Gastrotricha have been known since the 1850s, despite the fact that they are rather uncommon and difficult to collect. They are characterized by a round sack-shaped body, an absence of furcal adhesive tubes, and a different distribution of the locomotory ciliation compared to epibenthic and periphytic gastrotrichs. Today, planktonic gastrotrichs are classified into the three taxa—Dasydytidae, Neogosseidae, and Undula—but their origin and whether they share a recent common ancestor remain largely unknown. A long-held view is that planktonic taxa are derived from benthic ancestors related to Chaetonotus (Zonochaeta), but the hypothesis has never been properly tested. Here, in order to elucidate the phylogeny and origin of planktonic Gastrotricha, we provide the first molecular data on the very rare genera Kijanebalola and Neogossea, both members of the family Neogosseidae. We use Bayesian and maximum likelihood phylogenetics to analyze sequences of 18S rDNA, 28S rDNA, and COI mtDNA spanning 71 taxa in total. We find high support for a common origin of planktonic gastrotrichs, with monophyly of both Dasydytidae and Neogosseidae. Planktonic forms have evolved from epibenthic or periphytic ancestors, and the closest extant clade comprises members of Chaetonotus (Zonochaeta) + Chaetonotus heteracanthus Remane, 1927. These results further imply that the motile spines and underlying muscle patterns that control them in species of Dasydytidae are adaptations to the planktonic environment that evolved independently of those in other species of Gastrotricha.
Received: 13 January 2015 / Accepted: 23 April 2015 / Published online: 06 May 2015
Controversial patterns of Wolbachia infestation in the social parasitic Maculinea butterflies (Lepidoptera: Lycaenidae)Download PDFAbstract
Wolbachia is a common group of intracellular bacteria found in arthropods and filarial nematodes. Since the past decade, they have attracted considerable interest owing to their various effects on hosts, which range from reproductive manipulation to mutualism. Moreover, they can influence the mitochondrial DNA pattern which do not reflect the real evolutionary history of the target species and may be incongruent with nuclear data. Previously, Wolbachia-manipulated mitochondrial DNA (mtDNA) patterns, namely mito-nuclear discordance and deep mitochondrial splits associated with specific Wolbachia infections, have been also discovered in the genus Maculinea. Here, we present a comprehensive study on Wolbachia infestation and the genetic diversity of all Maculinea species in the Carpathian Basin. The prevalence and the pattern of the infestation highly differ among Maculinea species. Maculinea alcon and Maculinea arion are infected in 100 %, each of these species with a single strain, but the infection level of Maculinea nausithous and Maculinea teleius is much lower, additionally, they are infected with multiple strains. The genetic diversity of Maculinea species proved to be generally low, only M. nausithous showed geographic pattern based on mitochondrial sequences and allozymes. In contrast with the previous studies, we could not detect mito-nuclear discordance or find evidence for Wolbachia-induced selective sweep. Based on our results, we cannot hold only Wolbachia responsible for the restricted genetic diversity of Maculinea in the Carpathian Basin. Probably several factors shape together the level and pattern of genetic variability in Maculinea butterflies.
Received: 10 February 2015 / Accepted: 15 June 2015 / Published online: 27 June 2015
Functional morphology of the larval mouthparts of Panorpodidae compared with Bittacidae and Panorpidae (Insecta: Mecoptera)Download PDFAbstract
In Mecoptera, the larvae of Bittacidae and Panorpidae are saprophagous, but the feeding habit of larval Panorpodidae remains largely unknown. Here, we compare the ultramorphology of the mouthparts of the larvae among the hangingfly Bittacus planus Cheng, 1949, the scorpionfly Panorpa liui Hua, 1997, and the short-faced scorpionfly Panorpodes kuandianensis Zhong, Zhang & Hua, 2011 to infer the feeding habits of Panorpodidae. The molar region of Panorpodidae is glabrous, lacking the long spines for filtering (preventing larger particles from entering the pharynx) as found in Bittacidae or the tuberculate teeth for grinding as present in Panorpidae. The mandibles of Panorpodidae are unsuitable for grinding, and most likely, larval Panorpodidae have different feeding habits than larval Bittacidae and Panorpidae. The diversity of the larval feeding habits in Mecoptera and its evolutionary advantage are briefly discussed.
Received: 18 December 2014 / Accepted: 09 March 2015 / Published online: 03 April 2015
Two tribes hidden in one genus: the case of Agaedioxenis Villeneuve (Diptera: Tachinidae: Exoristinae)Download PDFAbstract
The Afrotropical tachinid “genus” Agaedioxenis Villeneuve is taken here as an example of the challenges faced by dipterists in classifying one of the most diverse and species rich families of organisms on Earth. Our study has revealed “two tribes hidden in one genus”, with one lineage representing a genus belonging to the tribe Goniini (Agaedioxenis) and the other representing a genus belonging to Eryciini (Eugaedioxenis gen. nov.). The two genera have been revised through an integrative approach of morphology and genetics (COI barcode sequences). The genus name Agaedioxenis replaces that of Gaedioxenis Townsend as a valid genus name. Agaedioxenis is recognized from five species consisting of two previously described species (Agaedioxenis setifrons (Villeneuve) and Agaedioxenis brevicornis (Villeneuve) both comb. nov.) and three new species (Agaedioxenis kirkspriggsi sp. nov., Agaedioxenis succulentus sp. nov., and Agaedioxenis timidus sp. nov.). Agaedioxenis propinqua (Villeneuve) is recognized as a subjective synonym of A. brevicornis (Villeneuve), syn. nov., and by First Reviser action, the latter is chosen as the senior of the two names. Eugaedioxenis gen. nov. is recognized based on two species, Eugaedioxenis haematodes (Villeneuve), type species and comb. nov., and Eugaedioxenis horridus sp. nov. All new species of both genera are described from South Africa. We further discuss how genetics, morphology, and natural history have contributed to revise the generic circumscription of Agaedioxenis, bringing about both the description of Eugaedioxenis and the revision of the suprageneric classification for these two taxa.
Received: 20 August 2014 / Accepted: 05 December 2014 / Published online: 24 December 2014
Cryptic and repeated “allopolyploid” speciation within Allium przewalskianum Regel. (Alliaceae) from the Qinghai-Tibet PlateauDownload PDFAbstract
Polyploidization has contributed greatly to current plant diversity. Allopolyploid speciation, which can rapidly overcome meiosis abnormalities, is a common and repeated process in numerous genera. However, most polyploids within a single morphological/taxonomic species have been considered autopolyploids, which were assumed to arise through spontaneous genome doubling and/or following the fusion of unreduced diploid gametes. It remains untested whether these intraspecific polyploids may also be the result of ‘allopolyploid’ hybridizations between differentiated diploid populations and whether such speciation has also occurred repeatedly. In this study, we examined the diploid–tetraploid species Allium przewalskianum on the Qinghai-Tibet Plateau (QTP) to test this cryptic speciation hypothesis under morphological stasis, based on three sets of nuclear genetic data (AFLP, ITS, and CHS) and niche modeling. Our analyses of the three datasets together revealed that the diploid populations across the northeastern to southeastern QTP exhibit strong geographical differentiation. Based on the shared nuclear lineages fixed in the different diploids, three tetraploid groups in the northern, southern, and eastern QTP were identified as having originated independently, through “allopolyploid” hybridization between the differentiated diploids. Ecological niche modeling based on ecological variables suggested distinct niche differentiation between two tetraploid groups in the northern and southern QTP and also between these and the diploid populations. Furthermore, they also differed in their responses to past climate changes. These findings together suggested that at least two tetraploid groups had originated independently through hybridizations between the differentiated diploid populations. Our results highlight the cryptic allopolyploid speciation underlying a single morphological species, which mirrors well the repeated allopolyploid speciations within the genus. This allopolyploid speciation may prevail within the diploid–polyploid species complex that is classified as a single morphological species; indeed, the underlying cryptic speciation and evolutionary dynamics are certainly more complex than previously assumed.
Received: 04 November 2014 / Accepted: 13 May 2015 / Published online: 09 June 2015
Uncovering the hidden diversity of the Neotropical butterfly genus Yphthimoides Forster (Nymphalidae: Satyrinae): description of three new species based on morphological and molecular dataDownload PDFAbstract
Three new species belonging to the butterflies satyrine subtribe Euptychiina are described: (1) Yphthimoides gabriela n. sp. occurring in low to medium altitudes in the coastal forests between the states of Rio de Janeiro and Bahia, (2) Yphthimoides bella n. sp., from Brazilian Cerrado savannas, known from only two localities in the State of Goiás, and (3) Yphthimoides iserhardi n. sp., occurring in high altitudes in the rocky outcrops of Chapada Diamantina, in the interior of the Bahia state. Descriptions are based on wing shape, wing pattern, and morphology of male genitalia. Furthermore, molecular data from the “DNA barcode” (Cytochrome C Oxidase I, ca. 658 bp) was obtained and used to validate the three new species. Additionally, information about geographic distribution and habitat for the three new species is provided, and the systematic position of each of the three species is discussed based on a molecular analysis using another 11 additional species of Yphthimoides.
Received: 15 September 2014 / Accepted: 03 March 2015 / Published online: 22 March 2015
Infectious intimacy and contaminated caves—three new species of ectoparasitic fungi (Ascomycota: Laboulbeniales) from blaniulid millipedes (Diplopoda: Julida) and inferences about their transmittal mechanismsDownload PDFAbstract
Laboulbeniales is an order of more than 2000 species of small ascomycete fungi which are ectoparasites of insects, millipedes and mites. They are often highly host-specific and often are also highly specific with regard to which body parts they infect. Laboulbeniales from millipedes are particularly poorly known—only 12 species have been described until now, mostly from Europe. Here, we describe the first laboulbeniaceous parasites from blaniulid millipedes: Troglomyces bilabiatus from Acipes spp., Troglomyces pusillus from Iberoiulus cavernicola Ceuca, 1967 and Troglomyces triandrus from Archiboreoiulus palidus (Brade-Birks, 1920). The generic description of Troglomyces is emended. Different types of site specificity of the three new parasites, as well as of previously described species, are explained in terms of aspects of host biology: mating behaviour and habitat. Species from epigean hosts tend to show a high degree of site specificity suggesting transfer during host copulation, whereas most species from cave hosts show no pronounced site specificity and are probably transferred via the substrate. Possible roles of host defensive secretions and parthenogenesis in relation to infection with Laboulbeniales are briefly discussed.
Received: 12 December 2014 / Accepted: 05 May 2015 / Published online: 17 May 2015
How many taxa? Spatiotemporal evolution and taxonomy of Amphoricarpos (Asteraceae, Carduoideae) on the Balkan PeninsulaDownload PDFAbstract
Amphoricarpos Vis. is an early diverging genus within tribe Cardueae (Carduoideae, Asteraceae), which is disjunctly distributed in the Balkan Peninsula, Anatolia and the Caucasus; the Anatolian and Caucasian taxa are sometimes treated as separate genus Alboviodoxa. We focus on the monophyletic Balkan populations, which have been treated very inconsistently in previous taxonomic accounts (one polymorphic species with or without varying sets of intraspecific taxa vs. two species, one of them with two subspecies). In order to disentangle relationships among populations across the entire distribution area of Amphoricarpos on the Balkan Peninsula, we employed amplified fragment length polymorphisms (AFLPs) as well as nuclear and plastid DNA sequences (ITS and rps16–trnK) to a dense sampling of populations. ITS was also used to reconstruct the genus’ spatiotemporal evolution. In addition, we contrasted the genetic results with morphological data to provide a sound taxonomic revision of Amphoricarpos on the Balkan Peninsula. The split between the Balkan populations and the Anatolian A. exsul took place in the late Miocene or early Pliocene, whereas diversification within the Balkan lineage is much younger and likely started in the Pleistocene. The deepest splits seen in AFLPs and/or ITS separate the geographically disjunct northern- and southern-most populations. Divergence within the continuous distribution area in the centre is shallower, but allowed recognition of three largely allopatric clusters. Morphometric data, however, were neither in line with previous multi-taxon treatments nor with patterns of genetic divergence. We therefore refrain from recognising any of the genetic groups as a distinct taxonomic entity and rather suggest treating all Balkan populations as a single, genetically, morphologically and ecologically variable species, Amphoricarpos neumayerianus (Vis.) Greuter, without intraspecific taxa.
Received: 05 November 2014 / Accepted: 14 January 2015 / Published online: 31 January 2015
Neurogenesis in directly and indirectly developing enteropneusts: of nets and cordsDownload PDFAbstract
Concerning the evolution of deuterostomes, enteropneusts (acorn worms) occupy a pivotal role as they share some characteristics with chordates (e.g., tunicates and vertebrates) but are also closely related to echinoderms (e.g., sea urchin). The nervous system in particular can be a highly informative organ system for evolutionary inferences, and advances in fluorescent microscopy have revealed overwhelming data sets on neurogenesis in various clades. However, immunocytochemical descriptions of neurogenesis of juvenile enteropneusts are particularly scarce, impeding the reconstruction of nervous system evolution in this group. We followed morphogenesis of the nervous system in two enteropneust species, one with direct (Saccoglossus kowalevskii) and the other with indirect development (Balanoglossus misakiensis), using an antibody against serotonin and electron microscopy. We found that all serotonin-like immunoreactive (LIR) neurons in both species are bipolar ciliary neurons that are intercalated between other epidermal cells. Unlike the tornaria larva of B. misakiensis, the embryonic nervous system of S. kowalevskii lacks serotonin-LIR neurons in the apical region as well as an opisthotroch neurite ring. Comparative analysis of both species shows that the projections of the serotonin-LIR somata initially form a basiepidermal plexus throughout the body that disappears within the trunk region soon after settlement before the concentrated dorsal and ventral neurite bundles emerge. Our data reveal a highly conserved mode of neurogenesis in enteropneusts that is independent of the developing mode and is inferred to be a common feature for Enteropneusta. Moreover, all detected serotonin-LIR neurons are presumably receptor cells, and the absence of serotonin-LIR interneurons from the enteropneust nervous system, which are otherwise common in various bilaterian central nervous systems, is interpreted as a loss that might have occurred already in the last common ancestor of Ambulacraria.
Received: 16 February 2015 / Accepted: 20 July 2015 / Published online: 09 August 2015
Ancient divergence and recent population expansion in a leaf frog endemic to the southern Brazilian Atlantic forestDownload PDFAbstract
The evolutionary history of Neotropical organisms has been often interpreted through broad-scale generalizations. The most accepted model of diversification for the Brazilian Atlantic forest (BAF) rely on putative historical stability of northern areas and massive past habitat replacement of its southern range. Here, we use the leaf frog Phyllomedusa distincta, endemic to the southern BAF, to better understand diversification patterns within this underexplored rainforest region. We used an integrative approach coupling fine-scale sampling and multilocus sequence data, with traditional and statistical phylogeographic (multilocus approximate Bayesian computation) methods to explore alternative hypotheses of diversification. We also employed species paleodistribution modeling to independently verify habitat stability upon a spatially explicit model. Our data support two divergent lineages with coherent geographic distribution that span throughout northern and southern ranges. Demographic estimates suggested the Southern lineage has experienced a recent population expansion, whereas the Northern lineage remained more stable. Hypothesis testing supports a scenario of ancient vicariance with recent population expansion. The paleodistribution model revealed habitat discontinuity during the Last Glacial Maximum (LGM) with one area of putative stability within the range of the Northern lineage. Evidence on genetic structure, demography, and paleodistribution of P. distincta support a historically heterogeneous landscape for the southern BAF, with both areas of forest stability and regions where forest occupation is probably recent. We also associate the southern end of the Cubatão shear zone with a phylogeographic break in the BAF. Taken together, our results argue for the idea of multiple mechanisms generating diversity in this biome and underscore the need of fine-scale data in revealing more detailed pictures.
Received: 27 February 2014 / Accepted: 29 October 2014 / Published online: 11 December 2014
Phylogenetic evidence for multiple independent origins of functional kleptoplasty in Sacoglossa (Heterobranchia, Gastropoda)Download PDFAbstract
Sacoglossa is a rather small taxon of marine slugs with about 300 described species, yet it is quite fascinating scientists for decades. This is mainly because of the ability of certain species to incorporate photosynthetically active plastids of their algae prey, a phenomenon known as functional kleptoplasty. With the stolen plastids, these slugs endure weeks (short-term retention) or months (long-term retention) of starvation, though contribution of the plastids to the survival and factors enhancing plastid longevity are unknown. Likewise, contrasting hypotheses on evolution of functional kleptoplasty exist and the phylogenetic relationship of Sacoglossa taxa is still under debate. We analyzed the phylogenetic relationship of 105 sacoglossan species to address the question of the origin of functional kleptoplasty. Based on our phylogenetic analysis and the ancestral character state reconstruction, we conclude that functional short-term retention most likely originated two times and long-term retention at least five times. Previous suggestions that functional long-term kleptoplasty is established with specific plastids are supported by our food analyses in Elysia clarki that finally harbors only plastids of certain algae species over a prolonged starvation period.
Received: 02 September 2014 / Accepted: 13 May 2015 / Published online: 31 May 2015
The hypothesis of adaptive radiation in evolutionary biology: hard facts about a hazy conceptDownload PDFAbstract
Adaptive radiation is one of the most emblematic concepts in evolutionary biology. However, the current lack of a consensual definition and the diversity of methods used to assess the extent and speed of adaptive radiation indicate the need for a reappraisal of this research field. In order to depict how adaptive radiations have been studied in recent years, we performed a scientometric assessment of 765 articles published between 2003 and 2012 in five journals known to serve a broad audience. From each study, we extracted and analyzed data relative to the taxon and geographical area investigated and to the methodological setup, and we categorized its outcomes and conclusions. This scientometry-oriented work allowed us to identify and discuss trends relative to the way research about adaptive radiations was carried out during the 10-year period starting in 2003. We then provided some recommendations for how to conduct a reliable study of a suspected adaptive radiation. The associated database resulting from our study will be a valuable source of information for biologists as they design a study or put their results in perspective. Our work may also inspire a critical assessment of the relevance of this pivotal concept in evolutionary biology.
Received: 08 April 2014 / Accepted: 15 December 2014 / Published online: 30 December 2014
Evidence of ancient horizontal gene transfer between fungi and the terrestrial alga Trebouxia
Intimate and long-lasting relationships of fungi and algae have been known for centuries by scientists, and these ancient symbioses might have provided excellent opportunities for horizontal gene transfer (HGT) of protein encoding genes between the two organismal partners. In this study, we sequenced and assembled 451 Mbp of novel genomic DNA from Trebouxia decolorans (Trebouxiaceae, Chlorophyta), the green algal photobiont of the lichen Xanthoria parietina (Teloschistaceae, Lecanoromycetes, Ascomycota). This alga also occurs as a free-living terrestrial organism. The aim of our work was to search for candidate genes pointing to HGT between lichenized fungi and lichen algae. We found evidence for three putative HGT events of fungal genes into the Trebouxia genome, but these are likely more ancient (over 600 mya) than the origin of lichenization within the fungal Ascomycetes. The three transferred genes are part of gene groups that in other species encode a tellurite-resistance dicarboxylate transporter (TDT) family protein, a class-1 nitrilase/cyanide hydratase (CH), and an oxidoreductase/retinol dehydrogenase. In each case, our phylogenomic analyses show orthologs from Trebouxia as sister to orthologs from all fungi or basally placed within Ascomycetes, while the orthologs from green algae and land plants form separate, independent evolutionary lineages. Alternative hypothesis tests significantly support these HGT events. The presence of these genes in Trebouxia was validated by PCR amplification of separately isolated Trebouxia DNA. The ancient incorporation of fungal genes in the genomes of these particular green algae are intriguing and could be early evidence for symbiotic and co-evolutionary relationships among the major eukaryotic branches of algae and fungi present in early terrestrial life on Earth. These genes could have played a pre-disposition role for some fungi and algae in the origin of lichen symbiosis, but further studies are needed to evaluate this in detail.
Received: 03 October 2014 / Accepted: 26 January 2015 / Published online: 11 February 2015
Phylogeny of the Peckia-genus group: evolution of male genitalia in the major necrophagous guild of Neotropical flesh flies (Diptera: Sarcophagidae)Download PDFAbstract
Peckia is the most species-rich necrophagous genus among the Neotropical sarcophagids, encompassing 67 species distributed in 5 subgenera. Recent phylogenetic studies have challenged the monophyly of this genus with regard to species of the genera Peckiamyia, Titanogrypa, and Villegasia, and the genera Engelimyia, Helicobia, Retrocitomyia, and Sarcophaga. These genera have variously been hypothesized as sister groups to Peckia, or genera closely related to it. We applied cladistic methods using both molecular and morphological data to study phylogenetic relationships of these mostly necrophagous taxa. All currently recognized species of Peckia were included in our analysis. Based on 116 morphological characters and sequences of five gene fragments, we corroborate the recent division of Peckia into five subgenera, and we argue that the reduction of the acrophallic median stylus is an autapomorphic condition supporting the clade (Peckia + (Lipoptilocnema (Helicobia + Sarcophaga))). Our analysis shows that Peckiamyia is sister to Retrocitomyia, and Titanogrypa is sister to Villegasia, which together with Engelimyia form lineages that emerge in a basal divergence with regard to the clade with no median stylus. Alternative homology interpretations of the median stylus were studied and tested in a phylogenetic context. The median stylus and other phallic homologies were revisited and redefined. All studied genera were found to be monophyletic.
Received: 17 July 2014 / Accepted: 15 December 2014 / Published online: 30 December 2014
Divergent evolutionary pathways and host shifts among the commensal pontoniine shrimps: a preliminary analysis based on selected Indo-Pacific speciesDownload PDFAbstract
As the most species-rich subfamily of Caridea, Pontoniinae Kingsley, 1878 is well-known for its great diversity in morphology, lifestyle and habitat. However, the phylogeny of Pontoniinae has been poorly studied since it was erected, and there are many taxonomic and evolutionary controversies remained unresolved. Among these controversies, the relationship between the commensal pontoniine shrimps and their hosts is the issue of most concern. Herein, a total of 26 Indo-Pacific pontoniine species from 23 genera, including both free-living and commensal taxa associated with different marine organisms from five phyla, are selected to preliminarily explore the differentiation process accompanied with the reciprocal natural selections between them and their hosts. Based on the molecular phylogenetic analyses, two major clades, representing the ‘primitive groups’ and ‘derived groups’, and several subgroups related to the hosts are well recovered, which are also supported in morphology. Additionally, several possible evolutionary pathways of those commensal pontoniine shrimps with similar hosts or niches are identified, with a host-shifting hypothesis proposed for cavity-inhabiting pontoniines based on molecular data in conjunction with morphological and ecological evidence.
Received: 10 February 2015 / Accepted: 15 July 2015 / Published online: 31 July 2015
Ecomorphology of Carnivora challenges convergent evolutionDownload PDFAbstract
Convergent evolution is often reported in the mammalian order Carnivora. Their adaptations to particularly demanding feeding habits such as hypercarnivory and durophagy (consumption of tough food) appear to favour morphological similarities between distantly related species, especially in the skull. However, phylogenetic effect in phenotypic data might obscure such a pattern. We first validated the hypotheses that extant hypercarnivorous and durophagous large carnivorans converge in mandibular shape and form (size and shape). Hypercarnivores generally exhibit smaller volumes of the multidimensional shape and form space than their sister taxa, but this pattern is significantly different from random expectation only when hunting behaviour categorisations are taken into account. Durophages share areas of the morphospace, but this seems to be due to factors of contingency. Carnivorans that hunt in pack exhibit incomplete convergence while even stronger similarities occur in the mandible shape of solitary hunters due to the high functional demands in killing the prey. We identified a stronger phylogenetic signal in mandibular shape than in size. The quantification of evolutionary rates of changes suggests that mandible shape of solitary hunters evolved slowly when compared with other carnivorans. These results consistently indicate that the need for a strong bite force and robust mandible override sheer phylogenetic effect in solitary hunters.
Received: 10 December 2013 / Accepted: 03 November 2014 / Published online: 24 December 2014
New Ichthyophis species from Indochina (Gymnophiona, Ichthyophiidae): 1. The unstriped forms with descriptions of three new species and the redescriptions of I. acuminatus Taylor, 1960, I. youngorum Taylor, 1960 and I. laosensis Taylor, 1969Download PDFAbstract
Caecilians of the genus Ichthyophis Fitzinger, 1826 are among the most poorly known amphibian taxa within Southeast Asia. Populations of Ichthyophis from the Indochina region (comprising Cambodia, Laos, and Vietnam) have been assigned to five taxa: Ichthyophis acuminatus, Ichthyophis bannanicus, Ichthyophis kohtaoensis, Ichthyophis laosensis, and Ichthyophis nguyenorum. Barcoding of recently collected specimens indicates that Indochinese congeners form a clade that includes several morphologically and genetically distinct but yet undescribed species. Although body coloration is supported by the molecular analyses as a diagnostic character at species level, unstriped forms are paraphyletic with respect to striped Ichthyophis. Based on our morphological and molecular analyses, three distinct unstriped ichthyophiid species, Ichthyophis cardamomensis sp. nov. from western Cambodia, Ichthyophis catlocensis sp. nov. from southern Vietnam, and Ichthyophis chaloensis sp. nov. from central Vietnam are described as new herein, almost doubling the number of Ichthyophis species known from the Indochinese region. All three new species differ from their unstriped congeners in a combination of morphological and molecular traits. In addition, redescriptions of three unstriped Ichthyophis species (Ichthyophis acuminatus, I. laosensis, I. youngorum) from Indochina and adjacent Thailand are provided.
Received: 09 December 2014 / Accepted: 13 February 2015 / Published online: 27 February 2015
A phylogeny of Sericini with particular reference to Chinese species using mitochondrial and ribosomal DNA (Coleoptera: Scarabaeidae)Download PDFAbstract
Sericini chafer beetles are inconspicuous and morphologically rather uniform. Their morphological homogeneity has resulted in taxonomic difficulties particularly with the generic classification but also with the recognition of the species in general. Here, we present a phylogenetic analysis of Sericini using maximum likelihood and Bayesian tree inference based on partial 28S ribosomal DNA (rDNA), cytochrome oxidase I (cox 1), and 16S rDNA (rrnL) for 26 genera and 173 species of Sericini, with major focus on Chinese taxa. Chinese taxa were resolved within two major clades of the subtribe Sericina, while basal lineages of Sericini as well as Trochalina did not include species from China. Our results confirm previous findings in which species relationships were not consistent with the current genus-level classification, as well as in a previously hypothesized close phylogenetic link between southwestern Chinese and Himalayan species. Large genera such as Neoserica, Serica, and Maladera all resulted to be polyphyletic, being split in several distantly related branches. But also, less intensely sampled groups like Lasioserica and Microserica were non-monophyletic. The major implication from this analysis is that the existing taxonomic system needs to be significantly revised by integrating morphology carefully in the context of a robust backbone phylogeny to allow delineation of monophyletic but unambiguously diagnosable genera.
Received: 07 September 2014 / Accepted: 21 January 2015 / Published online: 07 February 2015
Lack of well-maintained natural history collections and taxonomists in megadiverse developing countries hampers global biodiversity explorationDownload PDFAbstract
Recently, there have been controversial discussions regarding the decline in the number of taxonomists as the main bottleneck for the discovery and complete assessment of global biodiversity. In addition, we here review and highlight the eminent role of natural history collections in exploring the global species diversity by discussing the current conditions of institutional infrastructure in biologically megadiverse developing countries (MDCs). To our knowledge, this is the first critical assessment, which primarily focuses on these biologically wealthy nations. We show that in addition to the taxonomists’ shortage, the lack of well-maintained collection infrastructure represents the main bottleneck for biodiversity exploration in MDCs. No campaign to inventory biodiversity at national or global scale in a foreseeable timeframe can be successful without the creation of more positions for taxonomists and the expansion of existing or the establishment of new natural history collections in MDCs, respectively. Considering the lack of sufficient financial resources in many MDCs, we suggest that joint political priority of industrialized and developing countries should be given to the enduring maintenance and sustainable support of institutional infrastructures, if Convention on Biological Diversity targets for 2020 are to be addressed expediently.
Received: 27 October 2014 / Accepted: 15 April 2015 / Published online: 03 May 2015
Biogeography, cryptic diversity, and queen dimorphism evolution of the Neotropical ant genus Ectatomma Smith, 1958 (Formicidae, Ectatomminae)Download PDFAbstract
Due to its high biodiversity and its complex climatic and geological history, the Neotropical region has caught the attention of evolutionary and conservation biologists. The Neotropics have an understudied and probably extensive cryptic diversity, stemming from old lineages that have persisted through time with highly similar morphology or from new morphologically undifferentiated sibling species. The wide-ranging Neotropical ant genus Ectatomma currently has only 15 described species, some of which present limited distribution. These ants provide an excellent system for the study of diversification and cryptic diversity in the Neotropics. Ectatomma also displays queen-size dimorphism in some northern populations of its two most common species: a case of true microgyny and a recently described parasitic species. We performed a phylogenetic and biogeographic analysis of Ectatomma species using two mitochondrial genes and one nuclear gene. We also explored the relationship between the history of the genus and the appearance of miniaturized queens. Our analysis recovered a monophyletic Ectatomma that originated in the Parana region of South America. We recorded three likely events of colonization of the Caribbean–Mesoamerican region. We also detected ample evidence of cryptic divergence that deserves a full taxonomic revision of the genus. Miniature queens—microgynes and parasites—represent two independent evolutionary events that appeared in the recent history of the genus.
Received: 17 November 2014 / Accepted: 13 February 2015 / Published online: 01 March 2015
Structure and ultrastructure of eyes of tornaria larvae of Glossobalanus marginatus
Enteropneusts or acorn worms are marine deuterostomes that have retained many plesiomorphic characters. Thus, enteropneusts are of prime interest in evolutionary comparisons between deuterostomes and protostomes. In the present study, the larval eyes of Glossobalanus marginatus were reconstructed and described based on serial sectioning for transmission electron microscopy. The everse eyes of the late Metschnikoff/early Krohn-stage tornaria larvae of G. marginatus are epidermal structures consisting of two rows of in total 13 shading pigment cells and another two rows of 13 photoreceptor cells. The pigment cells form a shallow cup with a relatively wide opening, making the cup-shaped eye optically unsuitable for picture generation. We demonstrate that the photosensitive cells possess numerous enlarged microvilli and an unmodified apical cilium. Our ultrastructural studies thus corroborate the photoreceptor cells in the eye of G. marginatus to be of a clearly rhabdomeric type. Preliminary immunohistochemical experiments support those findings by demonstrating immunopositive reaction of the tornarian eye photoreceptors with an antibody designed against rhabdomeric sea urchin photopigment (Sp-Opsin4). Observations of living animals indicate that Late Metschnikoff/early Krohn-stage tornaria larvae are negatively phototactic, probably concordant with imminent metamorphosis.
Received: 17 March 2015 / Accepted: 05 June 2015 / Published online: 19 June 2015
Low connectivity between ‘scaly-foot gastropod’ (Mollusca: Peltospiridae) populations at hydrothermal vents on the Southwest Indian Ridge and the Central Indian RidgeDownload PDFAbstract
Hydrothermal vents on mid-oceanic ridges are patchily distributed and host many taxa endemic to deep-sea chemosynthetic environments, whose dispersal may be constrained by geographical barriers. The aim of this study was to investigate the connectivity of three populations of the ‘scaly-foot gastropod’ (Chrysomallon squamiferum Chen et al., 2015), a species endemic to hydrothermal vents in the Indian Ocean, amongst two vent fields on the Central Indian Ridge (CIR) and Longqi field, the first sampled vent field on the Southwest Indian Ridge (SWIR). Connectivity and population structure across the two mid-oceanic ridges were investigated using a 489-bp fragment of the cytochrome oxidase c subunit I (COI) gene. Phylogeographical approaches used include measures of genetic differentiation (F
ST), reconstruction of parsimony haplotype network, mismatch analyses and neutrality tests. Relative migrants per generation were estimated between the fields. Significant differentiation (F
ST = 0.28–0.29, P < 0.001) was revealed between the vent field in SWIR and the two in CIR. Signatures were detected indicating recent bottleneck events followed by demographic expansion in all populations. Estimates of relative number of migrants were relatively low between the SWIR and CIR, compared with values between the CIR vent fields. The present study is the first to investigate connectivity between hydrothermal vents across two mid-ocean ridges in the Indian Ocean. The phylogeography revealed for C. squamiferum indicates low connectivity between SWIR and CIR vent populations, with implications for the future management of environmental impacts for seafloor mining at hydrothermal vents in the region, as proposed for Longqi.
Received: 29 October 2013 / Accepted: 06 October 2014 / Published online: 21 October 2014
Distribution of Tomicus destruens (Coleoptera: Scolytinae) mitochondrial lineages: phylogeographic insights and niche modellingDownload PDFAbstract
This paper presents a novel approach of population genetics together with environmental and biogeographic data leading to inferences for ecological niche modelling. We used hierarchical lineages obtained using the nested cladistic analysis (NCA) of the mitochondrial DNA (mtDNA) haplotypes of the bark beetle species Tomicus destruens, for modelling the distribution by maximum entropy using environmental and host variables along the whole Mediterranean Basin. The identity and similarity tests were checked in the intraspecific lineages (NCA clades and haplotypes) in order to determine a shift or conservatism niche between them. Also, four indices from nine geographical areas in the Mediterranean Basin were calculated to assess the variability of environmental factors shaping the distribution of haplotype diversity on a large geographic scale. The ecological models developed indicate that minority eastern mtDNA lineages of T. destruens differ in their potential ecological niche according to their relation to extreme climatic variables. By contrast, the most widespread western lineages display a close relationship with their Pinus host tree. Also, higher levels of exclusive and endemic haplotypes were predicted in areas with high temperature variability in the Mediterranean wet period. The eastern group niche seems to be included in part of the range of the ecological space of the two major western clades. This result suggests that a niche shift might have started, being still an early relationship with its host tree Pinus brutia. Alternatively, the temperature variability in the wettest period appears to be related to a high proportion of endemic haplotypes of T. destruens, possibly by involving a balance between the length of the flight reproductive period of T. destruens and the status of the host tree vigour and growth stage. This study illustrates a good example of the benefits that ecological niche modelling provides to understand population genetic and phylogeographic patterns.
Received: 03 February 2015 / Accepted: 15 April 2015 / Published online: 24 May 2015
Review of the Plangia graminea (Serville) complex and the description of new Plangia species from East Africa (Orthoptera: Phaneropteridae, Phaneropterinae) with data on habitat, bioacoustics, and chromosomesDownload PDFAbstract
The Plangia graminea complex is partly reviewed and two new species of Plangia are described, Plangia multimaculata n. sp. from savanna habitats and Plangia satiscaerulea n. sp. from the submontane zones in northern Tanzania. Plangia compressa (Walker 1869) is synonymized with P. graminea (Serville, 1838). Data on habitat, bioacoustics, and chromosomes are provided. Both analyzed Plangia species showed the same chromosomal number. Compared to other investigated African Phaneropterinae, Plangia had a reduced chromosome number and thus shows a derived condition in its genome. The sex chromosomes differed morphologically in both investigated species of Plangia suggesting different mechanisms leading to these differences. Niche specialization and the male calling song are discussed as drivers for speciation in fully alate and thus mobile taxa.
Received: 20 July 2014 / Accepted: 03 November 2014 / Published online: 19 November 2014
Morphology and molecules reveal two new species of the poorly studied gecko genus Paragehyra (Squamata: Gekkonidae) from MadagascarDownload PDFAbstract
We provide new morphological and genetic data on a poorly studied genus of geckos from Madagascar (Paragehyra) previously thought to be distributed only in the south-east and south-west of the island and discuss the biogeography and evolution of this genus. Two species (Paragehyra petiti and Paragehyra gabriellae) were formerly included in this genus, whose phylogenetic and biogeographical relationships remain unresolved. This morphological and molecular study enables the recognition of two new rock-dwelling species that are here formally described. Paragehyra felicitae sp. nov. has only been observed in the private Anja reserve and nearby areas (close to Ambalavao) on the southern central high plateau of Madagascar, whereas Paragehyra austini sp. nov. is known from only one locality on the western slopes of the Andohahela massif, around 60 km northwest of Tolagnaro. The four species differ from one another by a combination of several morphological characters, genetic divergence >5.2 % in a mitochondrial 16S ribosomal RNA (rRNA) gene fragment and nucleotide differences in analysed nuclear genes, as highlighted in the resulting phylogenetic reconstruction and haplotype network analysis. A further, hitherto unstudied Paragehyra population is known from the Tsingy de Bemaraha in central-western Madagascar. Preliminary information of its morphological differentiation are here provided and suggest that this undescribed species is closely related to P. petiti and P. felicitae sp. nov.
Received: 12 February 2015 / Accepted: 10 April 2015 / Published online: 03 May 2015
New ambrosia beetles (Coleoptera: Curculionidae: Platypodinae) from Miocene Mexican and Dominican ambers and their paleobiogeographical implicationsDownload PDFAbstract
Two new species are described from Mexican amber (15–20 Ma): Cenocephalus tenuis Peris and Solórzano Kraemer sp. nov. and Tesserocerus simojovelensis Peris and Solórzano Kraemer sp. nov. Cenocephalus, originally described as living in Central and South America and then as fossils from Early to Middle Miocene amber, is noted as morphologically indistinguishable from Mitosoma, and originally described as endemic from Madagascar. Thus, we consider that a close taxonomic relationship exists, even if they are not the same genus. New evidence of the species already described in Platypodinae (Tesserocerini) from Mexican and Dominican ambers (15–20 Ma) and the differences between those species are discussed, complementing the original descriptions. The paleobiogeography of Cenocephalus and Mitosoma is analyzed, which strongly supports the hypothesis of colonization from Afrotropical Madagascar to America prior to Early to Middle Miocene (15–20 Ma) via sea currents. Hymenaea was interpreted as the Mexican and Dominican resin producers. Based on the analysis of fossil and current distribution of such plants, our hypothesis considers that the beetle dispersion occurred with Hymenaea, which was possibly its host plant.
Received: 07 November 2013 / Accepted: 05 December 2014 / Published online: 24 December 2014
Range of a Palearctic uraniid moth Eversmannia exornata (Lepidoptera: Uraniidae: Epipleminae) was split in the Holocene, as evaluated using histone H1 and COI genes with reference to the Beringian disjunction in the genus Oreta (Lepidoptera: Drepanidae)Download PDFAbstract
Large-scale climatic cycling during the Pleistocene resulted in repeated split and fusion of species ranges in high northern latitudes. Disjunctions of ranges of some Eurasian species associated with nemoral communities used to be dated to ‘glacial time’, with existence of their contiguous ranges reconstructed not later than 1 mya, while a recent hypothesis associates them with the Boreal time of the Holocene and reconstructs the contiguous ranges ca 5 thousand years ago. These estimates differing by almost 3 orders of magnitude appealed for their testing via molecular methods. We made such a test for Eversmannia exornata (Lepidoptera: Uraniidae: Epipleminae), the only uraniid moth inhabiting Siberia, the range of which is split into three pieces: East European, West Siberian and Far Eastern. Two genes were sequenced in specimens from one population from each geographical isolate: a fragment of the mitochondrial cytochrome c oxydase I (COI), frequently used for molecular phylogeny and barcoding, and a nuclear gene encoding histone H1. The COI gene fragment appeared to have two alleles differing by one synonymous substitution; both alleles co-occurring in the European population. The histone H1 gene had two dimorphic synonymous sites, with both variants of one site found in all three isolates. Absence of accumulated difference in both genes and polymorphism for the same synonymous substitution in the H1 gene in all three parts of the range suggests a very recent disjunction which cannot be resolved by coding gene sequences. This well corresponds to the Holocene disjunction hypothesis and rules out the Pliocene/early Pleistocene disjunction hypothesis. The published rate of the COI gene evolution was verified using the Beringian disjunction in the genus Oreta (Lepidoptera: Drepaniidae) as comparing two northernmost Asian and one American species which diverged not later than the Pliocene. The rate of substitution accumulation in the histone H1 gene was estimated as 0.48 of that of the COI gene, that is ca 3.6 × 10−9 substitutions per site per year. Four indels were found in the histone H1 gene in the three Oreta species studied, differing from each other not less than with two indels.
Received: 13 April 2015 / Accepted: 29 July 2015 / Published online: 07 August 2015
Differentiation of North African foxes and population genetic dynamics in the desert—insights into the evolutionary history of two sister taxa, Vulpes rueppellii and Vulpes vulpes
The effects of Pleistocene glaciations on moulding biodiversity have been extensively investigated within temperate biomes, yet arid ecosystems are largely neglected. A clear example comes from North Africa and the successive range of expansion/contraction cycles of the Sahara desert. This study focuses on North African foxes (genus Vulpes), in particular two sister taxa, Vulpes rueppellii and Vulpes vulpes, but also Vulpes zerda and Vulpes pallida. A set of two mitochondrial markers (Cyt-b and D-loop) and 31–33 autosomal microsatellites were used to conduct phylogenetic and population analyses, as well as to investigate the possible occurrence of hybridisation events. Phylogenetic analysis revealed V. rueppellii to be more closely related to North African V. vulpes than the latter with Eurasian V. vulpes, along with the occurrence of two sub-clades of V. vulpes within the Maghreb. In contrast, microsatellite analysis identified V. rueppellii and V. vulpes as clearly separate entities, and no sign of population structure was observed for both species within North Africa. Both mitochondrial and nuclear markers separated North African and Eurasian V. vulpes in two distinct groups. We propose two explanatory scenarios, both influenced by past climatic shifts: (1) past introgression of V. vulpes mitochondrial genome into V. rueppellii and (2) V. rueppellii represents an arid ecotype of V. vulpes trapped in the Sahara during a humid/arid transition. The successive expansions/contractions of the Sahara were also likely responsible for the mitochondrial structure of North African V. vulpes. We unveil intriguing insights on the genetic structure of carnivore species in North Africa, suggesting that further integrative research is needed.
Received: 17 April 2015 / Accepted: 28 July 2015 / Published online: 11 August 2015
Sex or no sex? Group I introns and independent marker genes reveal the existence of three sexual but reproductively isolated biospecies in Trichia varia (Myxomycetes)Download PDFAbstract
Plasmodial slime molds are members of the class Amoebozoa forming elaborate fruit bodies releasing airborne spores. Two species concepts have been developed independently: a morphological relying on fruit body characters, and a biological relying on crossing studies of a few cultivable species. In an attempt to reconcile both concepts, we obtained for 198 specimens of the common species Trichia varia partial sequences of three independent markers (nuclear small-subunit (SSU) ribosomal RNA gene, extrachromosomal; elongation factor 1 alpha gene, chromosomal; cytochrome oxidase subunit 1 gene, mitochondrial). The resulting phylogeny revealed 21 three-marker genotypes clustering into three groups. Combinations of the single-marker genotypes occurred exclusively within these groups, called 1, 2a, and 2b. To examine the suitability of group I introns to monitor speciation events, complete SSU sequences were generated for 66 specimens, which revealed six positions that can carry group I introns. For each of the groups 1 and 2a, five of these positions were occupied by different intron genotypes; and no genotype was shared by the two groups. Group 2b was devoid of introns. Putatively functional or degenerated homing endonuclease genes were found at different positions in groups 1 and 2a. All observations (genotypic combinations of the three markers, signs of recombination, intron patterns) fit well into a pattern of three cryptic biological species that reproduce predominantly sexual but are reproductively isolated. The pattern of group I introns and inserted homing endonuclease genes mounts evidence that the Goddard-Burt intron life cycle model applies to naturally occurring myxomycete populations.
Received: 10 July 2014 / Accepted: 24 November 2014 / Published online: 24 December 2014
Ecology, acoustics and chromosomes of the East African genus Afroanthracites Hemp & Ingrisch (Orthoptera, Tettigoniidae, Conocephalinae, Agraeciini) with the description of new speciesDownload PDFAbstract
The flightless Agraeciini genus Afroanthracites, a genus restricted to East Africa, is reviewed and two new species are described. Exemplary for the genus Afroanthracites, the ecological niche of Afroanthracites montium from Mt Kilimanjaro is defined. A. montium occupies habitats in humid and perhumid conditions and thus shows a broad altitudinal range (1250–2700 m). Concerning the acoustic communication, it is remarkable that within the micropterous genus a trend to low carrier frequencies is observed combined with the evolution of larger stridulatory organs (mirror; resonating part of tegmen). This trend starts with species using the same ultrasonic frequencies as a brachypterous out-group and ends with species presenting clearly audible songs. Cytogenetic data are given for five Afroanthracites and one Afroagraecia species. Differences in chromosome numbers Afroanthracites 2n = 29 and Afroagraecia 2n = 27 as well as a number of major rDNA clusters (one and two, respectively) are probably useful markers to separate both genera. It is discussed whether the African species evolved from a species with a presumably derived karyotype (e.g. 27 or 29 chromosomes) or if the proposed reduction of chromosome number occurred independently in Africa, Asia and Australia. The data set suggests that the African Agraeciini is of monophyletic origin, with a common ancestor of Afroagraecia and Afroanthracites in Africa. The Afroanthracites species can be divided into three groups on base of their morphology and colour pattern. Species of adjacent areas are morphologically sister groups. The most derived forms as seen in their morphology and acoustics are found in the West Usambara Mountains, part of the geologically old Eastern Arc Mountains.
Received: 08 June 2014 / Accepted: 15 April 2015 / Published online: 26 April 2015
Does size matter? Comparative population genetics of two butterflies with different wingspansDownload PDFAbstract
The dispersal ability of a species is central to its biology, affecting other processes like local adaptation, population and community dynamics, and genetic structure. Among the intrinsic, species-specific factors that affect dispersal ability in butterflies, wingspan was recently shown to explain a high amount of variance in dispersal ability. In this study, a comparative approach was adopted to test whether a difference in wingspan translates into a difference in population genetic structure. Two closely related butterfly species from subfamily Satyrinae, family Nymphalidae, which are similar with respect to all traits that affect dispersal ability except for wingspan, were studied. Melanitis leda (wingspan 60–80 mm) and Ypthima baldus (wingspan 30–40 mm) were collected from the same areas along the Western Ghats of southern India. Amplified fragment length polymorphisms were used to test whether the species with a higher wingspan (M. leda) exhibited a more homogenous population genetic structure, as compared to a species with a shorter wingspan (Y. baldus). In all analyses, Y. baldus exhibited greater degree of population genetic structuring. This study is one of the few adopting a comparative approach to establish the relationship between traits that affect dispersal ability and population genetic structure.
Received: 04 March 2014 / Accepted: 24 November 2014 / Published online: 03 December 2014
Morphological and molecular study of the genus Nitokra (Crustacea, Copepoda, Harpacticoida) in a small palaeochannel in Western AustraliaDownload PDFAbstract
A combined approach was used to study the diversity, distribution and variability of the ameirid genus Nitokra in the uppermost reaches of the Carey palaeochannel, as very little is known about habitat invasions of stygofauna in general and inland dispersal of this predominantly marine genus in particular. A 70-km-long stretch of several disconnected calcrete subterranean habitats, known as Yeelirrie, has previously shown to harbour up to ten sympatric and parapatric congeners of the miraciid genus Schizopera and six allopatric congeners of the parastenocaridid genus Kinnecaris, in addition to 11 other species of copepods. The diversity of the genus Nitokra is much smaller, with only two allopatric species in the entire area. Nitokra esbe sp. nov. is a short-range endemic, recorded in a single bore in the most downstream part of Yeelirrie. In contrast, both molecular and morphological data indicate that Nitokra yeelirrie sp. nov. is widespread here, showing one of the largest distribution ranges of any subterranean copepod in Yeelirrie. Phylogenetic analysis of Nitokra populations based on the COI gene shows N. esbe as a sister clade to other Nitokra sequences, which does not exclude the possibility of an ‘active upstream’ dispersal model, proposed for other copepods of marine origin here. High levels of COI sequence divergence (∼10 %) among specimens of N. yeelirrie collected 8 km apart suggest the potential for considerable population differentiation or restricted gene flow within an apparently single large calcrete body. A table of the most important morphological characters for all 79 valid world species of Nitokra is presented, and replacement names are provided for four junior homonyms. An overview of the conservation status of the entire Yeelirrie stygofauna was also provided.
Received: 23 February 2015 / Accepted: 20 July 2015 / Published online: 01 August 2015
Tachypleus syriacus (Woodward)—a sexually dimorphic Cretaceous crown limulid reveals underestimated horseshoe crab divergence timesDownload PDFAbstract
The fossil record represents an important test to molecular divergence estimates, with known occurrences representing minimum divergence times for sister taxa. As such, accurately placing fossils in phylogenies is integral to understanding the patterns and processes that shape the tree of life. The chelicerate order Xiphosura comprises classic archetypes of morphological stasis, with the earliest known Ordovician representatives exhibiting all key morphological characteristics of the group. Molecular studies on the four extant species consistently retrieve a basal split between Limulinae and Tachypleinae, but conflict regarding the relationships of the three Asian species. Molecular divergence estimates using either no or a single fossil calibration point infer a Cretaceous or Palaeogene origin for Limulidae and a Palaeogene or Neogene origin for Tachypleinae and Tachypleus. Here, we present male and female specimens of Tachypleus syriacus (=‘Mesolimulus’ syriacus) from the Cretaceous of Lebanon, revealing an anterior scalloped carapace margin in males—a derived condition of sexual dimorphism shared with Tachypleus tridentatus. Morphological phylogenetic analysis of total group Limulidae retrieves a monophyletic Tachypleus with a minimum divergence time during the Cretaceous, while crown-group Tachypleinae and Limulidae are both present during the Triassic, showing that molecular clock analyses have significantly underestimated the divergence times for these taxa.
Received: 20 August 2014 / Accepted: 11 May 2015 / Published online: 17 May 2015
Hidden diversity in the morphologically variable script lichen (Graphis scripta) complex (Ascomycota, Ostropales, Graphidaceae)Download PDFAbstract
Graphis scripta, or script lichen, is a well-known species of crustose lichenized fungi, widely distributed in the temperate region of the Northern Hemisphere. It is now considered to be a species complex, but because of the lack of secondary chemistry and paucity of measurable morphological characters, species delimitation within the complex has been challenging and is thus far based on apothecium and ascospore morphology. In this study, we employed molecular as well as morphological data to assess phylogenetic structure and delimitation of lineages within the G. scripta complex. We generated sequences for four genetic markers (mtSSU, nuLSU, RPB2, and EF-1) and performed phylogenetic analyses. The resulting trees were used to determine the number of distinct lineages by applying a general mixed Yule-coalescent (GMYC) model and species tree estimation through maximum likelihood (STEM). Our analyses suggest between six and seven putative species within the G. scripta complex. However, these did not correspond to the taxa that were recently distinguished based on apothecium morphology and could not be circumscribed with the morphological characters that were traditionally used in the classification of the complex. Any formal taxonomic treatment will require additional sampling and evaluation of additional traits that potentially can characterize these clades.
Received: 09 January 2015 / Accepted: 04 June 2015 / Published online: 11 July 2015
“Septal compass” and “septal formula”: a new method for phylogenetic investigations of the middle ear region in the squirrel-related clade (Rodentia: Mammalia)Download PDFAbstract
Here, we introduce the “septal compass” and the “septal formula” as a new method for phylogenetic investigations of the middle ear region in squirrel-related clade. The middle ear cavity is characterized by bony septa that divide the dorsally lying epitympanic recess and the ventrally lying tympanic cavity into several segments or diverticula. The distribution patterns of these septa are conservative among the squirrel-related clade and are restricted to the species, genus, and family level. In the studied outgroups represented by †Ischyromys typus and lagomorphs, no septa are found in the epitympanic recess and tympanic cavity. Therefore, the “septal compass” and the “septal formula” provide a new approach for phylogenetic interpretations of the middle ear region. It is user-optimized and can be modified for other rodent families and mammalian taxa and will facilitate phylogenetic assumptions in future investigations. Additionally, this method will enable the allocation of isolated tympanic bullae to the respective genus level.
Received: 30 May 2014 / Accepted: 12 September 2014 / Published online: 05 October 2014
Description of a new syllid species as a model for evolutionary research of reproduction and regeneration in annelidsDownload PDFAbstract
Syllids are one of the most speciose annelid taxa and characterized by their variety of reproductive modes. We provide the description of a new species of Syllidae (Annelida, Phyllodocida), Typosyllis antoni n. sp., which is characterized by its distinct color pattern consisting of transversal red lines on the dorsum of anterior segments; long antennae and dorsal cirri with strong alternation in length; bidentate chaetae falciger like with long spinulation on edge, one tiny and thin acicula appearing in posterior segments in addition to thicker and pointed one, and a long proventricle. A phylogenetic analysis of Syllinae based on three genes supports that T. antoni n. sp. is sister species to Typosyllis heronislandensis. This sister group relationship may indicate a common ancestor from the Pacific. Moreover, we recommend several steps to unify the taxonomy with phylogenetic knowledge of this group. Using immunocytochemistry coupled with confocal laser scanning microscopy (cLSM), we describe the internal morphology of this species. The body wall is composed of two dorsal and two ventral longitudinal muscle bundles that form a distinct inner layer. The outer or “circular layer” of body wall musculature is represented by prominent transverse muscle fibers that exhibit a semicircular arrangement. The musculature of the uniramous parapodia is characterized by distinct parapodial retractor muscles, acicular protractor muscles, as well as prominent acicular and chaetal flexor muscle bundles. T. antoni n. sp. reproduces by schizogamic scissiparity producing dicerous stolons. This species is able to regenerate the anterior end, including the prostomium, the first chaetae-less segment with all appendages, and some additional chaetigers, depending on the dissection side. Regeneration of the proventricle, ventricle, caeca, or pharyngeal tooth is not detectable. In contrast, regeneration of the posterior end appears to be complete. The available data makes T. antoni n. sp. to be one of the best investigated syllids, emphasizing its potential as model for the whole group. Our analysis establishes a framework for future studies on the evolution of reproductive modes in Syllidae, and we outline research questions how they are related to regeneration and development.
Received: 06 November 2012 / Accepted: 16 June 2014 / Published online: 12 December 2014
Comparative 3D microanatomy and histology of the eyes and central nervous systems in coleoid cephalopod hatchlingsDownload PDFAbstract
Adaptive radiation of an animal group is the evolutionary variation of morphology, physiology, and behavior opening up new habitats and resources. An impressive example of the reciprocal interdependency of form and function is found in the anatomy of cephalopod visual and central nervous systems. Interspecific differences of sensory organs and signal processing structures reflect the eco-functional context, e.g., the species-specific demands emanating from habitat and foraging behavior. To substantiate this, we investigated the eyes and brain neuropils of early post-hatching stages of six coleoid cephalopod species (Sepia officinalis, Rossia macrosoma, Sepietta obscura, Idiosepius notoides, Loligo vulgaris, and Octopus vulgaris), showing different size and inhabiting different ethoecological niches. Comprehensive 3D structure data sets were produced in light microscopic resolution, i.e., semithin section series of the head region (histology presented for I. notoides, R. macrosoma, and S. obscura for the first time) and 3D surface renderings of the neuropils, enabling the display of all components in arbitrary perspectives and combinations, and comparative volumetic anaylsis of homologous lobe neuropils. Differing in absolute size considerably, the visual and central nervous systems of the six species follow the same bauplan in adult-like configuration. The visual sense obviously is of paramount importance already after hatching, but also, equilibrioception and olfaction are well developed. The species-specific shapes of various components show that some plasticity and distinct differences in volumetric ratios are found, subject to their functional relevance and to different demands of the lifestyle on the brachial and swimming motor function, on camouflage, as well as on sensoric and cognitive abilities.
Published online: 19 November 2014
Erratum to: Multilocus population analysis of Gavia immer (Aves: Gaviidae) mtDNA reveals low genetic diversity and lack of differentiation across the species breeding rangeDownload PDF
Received: 23 July 2014 / Accepted: 20 October 2014 / Published online: 06 November 2014
Shell bone histology of solemydid turtles (stem Testudines): palaeoecological implicationsDownload PDFAbstract
Lately, solemydid turtles have been repeatedly recovered as stem Testudines, indicating that they belong to neither one of the two major branches of crown turtles, the Pancryptodira and Panpleurodira. Despite their wide temporal (Late Jurassic to Late Cretaceous) and spatial (North America and Europe) distributions, solemydid turtles are not particularly well known, as exemplified by the fact that only a single skull has been described for the whole group so far. Furthermore, the palaeoecology of solemydid turtles is still contested with hypotheses ranging from semi-aquatic to terrestrial lifestyles. However, the habitat preference of stem Testudines, such as solemydids, is important to understand the evolution and early radiation of the turtle crown, which is primitively aquatic. Here we describe the shell bone microanatomy and histological microstructures of solemydid turtles using a broad sample of taxa of different ages and localities, as well as review previous histological accounts, to elucidate the palaeoecology of the group independent of the geological setting and gross anatomy of the fossil finds. Our results indicate that Solemydidae share unique histological features pertaining to their strongly ornamented shell bones, which a) in cases allow taxonomic identification of even small shell fragments and b) unambiguously corroborate a terrestrial lifestyle of its members. The latter further supports a terrestrial lifestyle preference of most representatives of the turtle stem.
Received: 23 October 2014 / Accepted: 10 April 2015 / Published online: 28 April 2015
Review of the firefly visual system (Coleoptera: Lampyridae) and evolution of the opsin genes underlying color visionDownload PDFAbstract
Among insects, opsin copy number variation has been shown to be quite diverse. However, within the beetles, very little work on opsins has been conducted. Here, we look at the visual system of fireflies (Coleoptera: Lampyridae), which offer an elegant system in which to study visual evolution as it relates to their behavior and broader ecology. They are the best-known case of a terrestrial organism that communicates through the use bioluminescence. The molecular basis for this communication is relatively simple: one gene family (opsins) controls the detection of the signal, and one gene family (luciferase) controls the production of the signal. We use a transcriptomic approach to sample for and investigate opsin evolution in fireflies. We also use a phylogenetic estimate of Lampyridae to examine the evolution and ancestral modality of adult courtship communication. We find evidence for only two expressed opsin classes in each of the nine firefly species studied, one in the ultraviolet-sensitive and one in the long-wavelength-sensitive areas of the visible spectrum. Bioluminescent communication in adults is not optimized to be present ancestrally, and was gained two times with six subsequent losses. Despite the need for most adult fireflies to respond to a clearly sexual and colorful visual signal (bioluminescence) to maximize fitness, their visual system is relatively simple, and does not match the trend for opsin duplication found in other insect groups.
Received: 15 January 2015 / Accepted: 09 July 2015 / Published online: 26 July 2015
Parallel evolution of leaf morphology in gnetophytesDownload PDFAbstract
In the present paper, an ephedroid macrofossil species from the Early Cretaceous Yixian Formation of western Liaoning of China is described as new to science: Ephedra multinervia Yang et Lin, sp. nov. This species has typical ephedroid morphology, e.g. the dichasial branching shoot system, swollen nodes, internodes having many fine longitudinal striations and opposite phyllotaxy. Ephedra multinervia has strap-shaped leaves with multiple dichotomizing veins and reduced female cones with a single pair of fertile bracts forming a cupule enclosing two inner seeds. Ephedra multinervia is similar to Ephedra archaeorhytidosperma Yang et al. and Ephedra hongtaoi Wang et Zheng in its reduced bi-ovulate female cone, but differs from the latter two species by the lengthy strap-like leaves bearing multiple parallel veins and its sessile female cones. A new evolutionary hypothesis of the gnetophytes is proposed based on a synthesis of reproductive morphology of macrofossils from the Early Cretaceous and modern representatives. A Chengia-like precursor might have given rise to the Gnetum-Welwitschia clade by diversification of leaf morphology and female reproductive organs. According to this new explanation, the Welwitschia-like strap-like leaves with multiple parallel veins in E. multinervia result from convergence.