Search

The "Iberobathynella group", or Iberobathynellini tribe, is a complex of six genera consisting of 33 nominal species and several cryptic species with an amphiatlantic distribution (in Europe, North Africa and North America). A modern systematic revision of this group of subterranean crustaceans is presented here. A phylogenetic and biogeographic study using morphological and molecular data (mitocondrial coi and nuclear 18S) was carried out and allowed to a) re-evaluate the taxonomic status and validity of previously erected subtribes, genera and subgenera that show congruence in the data; b) assess whether the identified mitochondrial lineages represent cryptic species; c) provide a plausible phylogenetic hypothesis for the relationships within Iberobathynellini and with the other two genera of the family Parabathynellidae that inhabit North America and Europe (Montanabathynella and Parabathynella, respectively); d) propose a plausible temporal and historical framework (paleobiogeographic scenario) for the diversification and evolution of the Iberobathynellini tribe based on the current distribution of morphotypes and their estimated times of divergence. Our results show that in parabathynellids, molecular and morphological divergences are not always congruent. Subtribe and subgenus are invalid categories so they must be eliminated. Paraiberobathynella genus needs to be revisited. The molecular dating results support the early divergence of the Iberobathynellini Tribe (Upper Cretaceous, around 78 Mya) and the vicariance by plate tectonics as main factor to explain the amphi-Atlantic distribution shown by this ancient subterranean crustacean group. Since there are species morphologically very similar to I. magna and I. imuniensis, but genetically different, we can ensure the existence of at least three cryptic species. Texanobathynella is undoubtedly a valid genus distinct from Iberobathynella. Montanabathynella and Parabathynella are two well-differentiated genera closely related to the Iberobathynellini tribe. [ABSTRACT FROM AUTHOR]

The systematic status of the controversial crustacean family Leptobathynellidae is investigated using molecular and morphological methods in this study. Partial sequences of the nuclear 18S gene are studied from 28 genera of Bathynellacea from several continents. The analysis includes some of the most plesiomorphic genera of the family Parabathynellidae, such as Billibathynella and Brevisomabathynella from Australia; Habrobathynella and Parvulobathynella from India; the diverse Iberobathynella ; the cosmopolitan genus Hexabathynella ; and representative genera of two subfamilies of Bathynellidae (Gallobathynellinae and Bathynellinae). We used a molecular approach to analyse the systematic relationships amongst 64 species from Europe, North America, Australia and Asia, and review the morphological characters relevant at the family level. The molecular phylogeny clearly shows the presence of three highly divergent clades that could represent the three families. This is the first molecular phylogenetic reconstruction of Bathynellacea that can be used to: (1) verify the validity of Leptobathynellidae, (2) explore the diversity of the families and (3) explore the phylogenetic relationships among families. We propose a plausible evolutionary scenario for the order Bathynellacea. [ABSTRACT FROM AUTHOR]

Bathynellidae is the neglected family of Bathynellacea, a groundwater group of crustaceans with 33 genera and 107 species described and almost half of them included in the 'catch‐all' genus Bathynella. Due to the morphological homogeneity of the species, the taxonomic uncertainties have accumulated over time. Therefore, to explore the phylogenetic relationships among taxa, a combined approach using morphological and molecular data is needed. In this paper, we performed a phylogenetic analysis based on partial sequences of COI and 18S including 30 species of Bathynellidae. This data set represents the most updated one, including a new genus and a new species (Altainella calcarata gen. n. sp. n.) of Bathynellidae described here from Altai Mountain (Russia). The new taxon presents a new type of sexual dimorphisms with a peculiar structure on the coxopod of the male thoracopod VII and also sexual dimorphism on the mandibular palp, as some species of the subfamily Gallobathynellinae. This is the first species of Bathynellidae that presents both variants of sexual dimorphism. The molecular phylogeny supports the morphology and the erection of the new genus and displays highly divergent genetic units corresponding to subfamilies, with the new genus closer to Bathynellinae genera than other subfamilies. With the description of this new species and its molecular characterization, the existence of the other genera beyond Bathynella is confirmed in Eurasia. [ABSTRACT FROM AUTHOR]

A preliminary molecular phylogenetic framework for 12 genera (23 species) of the family Parabathynellidae from Europe, Australia, North Africa and India is presented based on mitochondrial and nuclear markers (Cox1 and 18S). The generated hypothesis places the Southeast Asia genus Paraeobathynella closer to European genera (Iberobathynella, Paraiberobathynella and Parabathynella) than to the Australian (Brevisomabathynella, Atopobathynella, Billibathynella, Octobathynella, Arkaroolabathynella and Lockyerenella) or Indian genera (Habrobathynella), or to the cosmopolitan genus Hexabathynella (Spain and Australia). Three new species of the genus Paraeobathynella from Thailand, P. ratensis n. sp., P. siamensis n. sp. and P. hanjavanitiana n. sp., are described based on morphological and molecular features. This is the first record of the genus from Thailand and extends its range of distribution within Asia, where it was previously known only from Vietnam. The new species are clearly separated as independent units at least since the Middle Miocene. [ABSTRACT FROM AUTHOR]

Bathynella natans Vejdovsky, 1882, the first described Bathynellidae species, was found in a well in Prague. Its original description was short and incomplete, and the holotype was already damaged in 1899. The lack of type material resulted in the poor description of the type genus of the morphologically very homogeneous family. This troubled beginning is the basis of a taxonomic problem that has led to the assignment of many species in Europe and other continents to the genus Bathynella. As currently understood, the genus is cosmopolitan, with more than 50 species and subspecies, most of them insufficiently described. We analyse the systematic position of the 29 genera and approximately 100 species. This analysis includes genera from Europe, USA and Western Australia, which have been characterized with molecular data (18S and COXI). In most cases, the genetic distances among genera and species are congruent with detected morphological differences. This is the first world molecular phylogenetic reconstruction of Bathynellidae, and it creates a framework for (1) confirming or discarding the cosmopolitan status of the genus Bathynella, (2) clarifying taxonomic uncertainties, (3) adequately describing new species, (4) advancing knowledge of the family's real diversity and (5) describing the phylogenetic relationships among genera from different continents. [ABSTRACT FROM AUTHOR]