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One of the main challenges to adequately conserve the African fish fauna is to improve our so far unsatisfactory taxonomic knowledge of important portions of the ichthyofauna. In the present study, we attempted to unravel the taxonomic diversity of some species of Enteromius Cope, 1867, a problematic African fish genus, recently collected in the north-eastern part of the Congo basin. We used an integrative approach, combining DNA barcodes and morphological analyses. For one of the species complexes found, the E. miolepis/eutaenia species complex, we evaluated taxonomic diversity over a larger geographic scale within the Congo drainage system. Although initial literature-based species identifications allowed us to assign all examined specimens to four tentative species, DNA barcodes indicated the presence of 23 distinct mitochondrial lineages. The majority of these lineages appeared endemic to particular rivers, and in most rivers multiple lineages occur in sympatry. Subsequent exploratory morphometric analyses indicated that almost all these lineages are morphologically distinguishable and that they may therefore represent undescribed species. As only a part of the Congo basin and a subset of the species diversity within Enteromius were examined, it appears that the species richness of Enteromius in the Congo basin is severely underestimated.
We describe a long-unnamed Chaetopterus Cuvier, 1830 species from southern California, using a combination of DNA barcoding and detailed morphological investigation employing highresolution X-ray microtomography (micro-CT). Chaetopterus dewysee sp. nov. is not only one of the most dominant annelids in the benthic communities of the shallow end of the La Jolla submarine canyon, but also a well-established model for studying bioluminescence and has a published transcriptome. The description and naming of this southern Californian Chaetopterus is a step towards the muchneeded revision of the group’s taxonomy and towards resolving the confusion over the 'cosmopolitan' Chaetopterus variopedatus species complex. Micro-CT data showing details of both internal and external anatomy has been made freely available as the first annelid cybertype.
The Western Ghats of India is considered one of the richest biodiversity hotspots in the world. Documenting scorpion diversity has always been of paramount importance due to their species richness, ecological role and endemism, which calls for conservation priority. Scorpion diversity of the Western Ghats is probably underestimated given the ancestry of the group, and more field work in the region is very likely to uncover numerous undescribed taxa. Several new Indian species have recently been discovered in the scorpion genus Isometrus Ehrenberg, 1828 (Scorpiones: Buthidae). In this communication, we resurrect I. sankeriensis Tikader & Bastawade, 1983 and describe two new species from the Western Ghats of India, I. nakshatra sp. nov. and I. wayanadensis sp. nov., using an integrative taxonomic approach. In order to replace the lost holotype of I. sankeriensis, we designate a neotype and reassess the identity of this species. This work elevates the number of species of Isometrus found in India to eight and we expect many more scorpion discoveries from India with continued research.
Neben biogeographischen werden morphologische Argumente zusammengetragen, die für eine Synonymisierung der Arten Acalles parvulus Boheman, 1837 = Acalles temperei Péricart, 1987 sprechen. Entlang eines Transekts zwischen dem Mont Pilat (Dep. Loire) und dem Mont Saint-Martin nördlich von Grenoble (Dep. Isère) wird über den Vergleich der Aedoeagi eine Cline sichtbar, die am Artstatus von Acalles temperei zweifeln lässt. Bestätigung finden diese vergleichenden, phänotypischen Untersuchungen durch erste molekulargenetische Untersuchungen. Danach scheint entweder eine Hybridisierungszone wahrscheinlich oder der Verdacht liegt nahe, dass Acalles parvulus und Acalles temperei eine einzige, geographisch strukturierte Art darstellen. Völlig anders liegen die molekularbiologischen Ergebnisse bei Kyklioacalles roboris (Curtis, 1834) und der erst kürzlich resynonymisierten Art Kyklioacalles navieresi (Boheman, 1837): Die DNA-Sequenzanalysen der mitochondrialen CO1- und 16S-Gene sowie des nukleären 28S-Gens zeigen, dass Kyklioacalles navieresi und Kyklioacalles roboris zwei eigenständige, wenn auch eng verwandte Arten darstellen.
In this paper we describe Macrobiotus canaricus sp. nov., a new tardigrade species of the Macrobiotus hufelandi group from the Canary Islands. Moreover, with the use of DNA sequencing, we confirm that Macrobiotus recens Cuénot, 1932 represents the hufelandi group, even though eggs laid by this species do not exhibit the typical hufelandi group morphology. Our study is based on both classical taxonomic methods that include morphological and morphometric analyses conducted with the use of light and scanning electron microscopy, and on the analysis of nucleotide sequences of four molecular markers (three nuclear: 18S rRNA, 28S rRNA, ITS-2, and one mitochondrial: COI). Our analyses revealed that M. canaricus sp. nov. is most similar to Macrobiotus almadai Fontoura et al., 2008 from the Archipelago of the Azores, from which it differs by the absence of granulation patches on the external and internal surfaces of legs I–III as well as by the absence of a cuticular pore in the centre of the external patch on legs I–III. Molecular sequences allowed us to pinpoint the phylogenetic positions of M. canaricus sp. nov. and M. recens within the M. hufelandi group.
Based on morphological and molecular data we investigated the species boundaries in the genus Ochraethes Chevrolat, 1860. The species delimitation with cytochrome c oxidase subunit 1 (COI) data supports some synonymies and highlights the existence of a high phenotypic plasticity in some species. The following species are considered as new junior synonyms: O. virescens (Chevrolat, 1860) syn. nov. of O. brevicornis (Chevrolat, 1860), O. octomaculata Chemsak & Noguera 2001 syn. nov. of Ochraethes cinereolus (Bates, 1892) comb. nov., O. zebratus Bates, 1885 syn. nov. of O. obliquus (Chevrolat, 1860), Trichoxys giesberti Botero, Santos-Silva & Wappes, 2019 syn. nov. of O. sommeri (Chevrolat, 1835), O. clerinus (Bates, 1892) of O. viridiventris (Chevrolat, 1860), O. cristoforii (Chevrolat, 1860) syn. nov. and O. litura Bates, 1885 syn. nov. of O. z-littera (Chevrolat, 1860). Two new species are described from Mexico: Ochraethes confusus sp. nov., and Ochraethes nigroapicalis sp. nov.
The ambersnails (Succineidae), found nearly worldwide, are considered a very challenging group to classify and identify with even genus-level identifications requiring dissection. In this study, we use mitochondrial and nuclear DNA markers, shell morphometrics, and anatomical dissection to examine fresh material collected from the type localities of two nominal species in Oxyloma (Neoxyloma). We conclude from these evidence that Oxyloma salleanum (L. Pfeiffer, 1850) and Oxyloma effusum (L. Pfeiffer, 1853) are conspecific, and accordingly reduce O. effusum to the status of junior synonymy. We present a redescription of O. salleanum.
Morphological and allozyme analyses suggested the occurrence of a pseudocryptic species in the Lasioglossum villosulum (Kirby, 1802) species complex (Hymenoptera: Halictidae). We analysed the morphology of more than 1500 specimens and the DNA barcode fragment of the cytochrome c oxidase subunit I (COI) of 102 specimens of this species complex from several Palaearctic countries. Our phylogenetic tree reconstructions, based on maximum likelihood and Bayesian inference revealed one clade corresponding to all specimens morphologically identified as Lasioglossum medinai (Vachal, 1895) and one divergent specimen morphologically identified as Lasioglossum berberum (Benoist, 1941). The other specimens, morphologically identified as L. villosulum, aggregated into at least three other lineages in our phylogenetic trees. The tree-based species delineations methods based on the Generalized Mixed Yule Coalescent (GMYC) model and the Bayesian Poisson Tree Process (bPTP) identified five to ten candidate species within the L. villosulum species complex, with L. medinai and L. berberum consistently recognized as separated from all other candidate species. Diagnostic morphological differences were found among L. medinai, L. berberum and the remaining specimens identified as L. villosulum. No diagnostic morphological differences were found to distinguish the different phylogenetic candidate species or lineages found within L. villosulum and L. medinai. Thus, both genetic and morphological approaches support the existence of L. medinai and L. berberum as distinct species from L. villosulum.
Polysyncraton Nott, 1892 is the second largest genus of didemnid ascidians; it has a wide distribution ranging from temperate to tropical waters. Seventy-one specimens of Polysyncraton from eight museum collections and recently collected samples were analyzed. This resulted in the description of three new species (P. cabofriense Oliveira & Rocha sp. nov. from Brazil, P. globosum Oliveira & Rocha sp. nov. from Australia and P. snelliusi Oliveira & Rocha sp. nov. from Suriname) and emended descriptions of three further species (P. amethysteum (Van Name, 1902), P. magnilarvum (Millar, 1962) and P. purou C. Monniot & F. Monniot, 1987).
A new species belonging to the crustacean class Remipedia is described from an anchialine cave system on the island of Cozumel (Mexico), and is illustrated and compared morphologically and molecularly (CO1 and 16S) with closely related taxa. Xibalbanus cozumelensis sp. nov., the first remipede described from Cozumel, is morphologically similar to Xibalbanus tulumensis (Yager, 1987) from the Yucatán Peninsula, but the two species are genetically separate from each other (about 10% in CO1). A phylogenetic (Bayesian) analysis of Yucatán remipede populations based on CO1 and 16S placed them in a monophyletic Xibalbanus (in Xibalbanidae fam. nov.), with X. cozumelensis as most closely related to X. tulumensis. The Yucatán Peninsula and Cozumel have been separate since approx. early Cenozoic (~65 Ma), which suggests allopatric speciation for X. cozumelensis sp. nov. and X. tulumensis. However, the comparatively low genetic divergence between the two species may indicate that there has been gene flow between ‘mainland’ Yucatán and Cozumel long after the geological separation of the two landmasses, e.g., in cave systems under the sea bed, either continuously or sporadically, for example during the Last Glacial Maximum when the sea level was about 120 m lower than today.