Morphological investigation of genital organs and first insights into the phylogeny of the genus Siciliaria Vest, 1867 as a basis for a taxonomic revision (Mollusca, Gastropoda, Clausiliidae).
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ABSTRACT:
SUBMITTER: De Mattia W
PROVIDER: S-EPMC8692307 | biostudies-literature | 2021
REPOSITORIES: biostudies-literature
Publications
Morphological investigation of genital organs and first insights into the phylogeny of the genus <i>Siciliaria</i> Vest, 1867 as a basis for a taxonomic revision (Mollusca, Gastropoda, Clausiliidae).
De Mattia Willy W Reier Susanne S Haring Elisabeth E
ZooKeys 20211214
Similar Datasets
Project description:BackgroundClausiliidae (door snails) are gastropods with a very high diversity concerning shell morphology, especially of their complex closing apparatus, which provides the most important diagnostic traits for classification of taxa. Due to the high variability, a high number of taxa has been described, though their systematics and taxonomy is partially controversially discussed. Montenegrina is the second most speciose door snail genus in Europe. It is an obligate rock-dwelling land snail and has, compared to its complex systematics, a rather small distribution range in the western parts of the Balkan Peninsula. The different taxa themselves show a very narrow and patchy distribution range. As Montenegrina is comprehensively sampled over the whole distribution range, it is a perfect study system for general questions on speciation and morphological differentiation in land snails. To study the amount of gene flow between geographically close or co-occurring populations, highly polymorphic markers are needed.ResultsThirteen microsatellite loci with a tetranucleotid repeat were isolated and tested in three geographically close Montenegrina populations (two populations of M. dofleini prespaensis from the Prespa Lake, n = 35 and one population from M. stankovici from the Ohrid Lake, n = 20). The number of alleles per locus ranged from 2 to 27. No significant linkage disequilibria between the same two loci were found in all three tested populations. The deviation from Hardy-Weinberg equilibrium reveal only for two loci a significant deviation from HWE in more than one population (Mont_5483 and Mont_4477).ConclusionThe 13 newly established genetic markers will help to gain better insights to the population genetic structure of Montenegrina and might reveal new results about speciation processes in co-occurring taxa. Furthermore, these microsatellite loci could also be tested in other clausiliid species.
| S-EPMC5364716 | biostudies-literature
Project description:The Neogastropoda (Mollusca, Gastropoda) encompass more than 15,000 described species of marine predators, including several model organisms in toxinology, embryology and physiology. However, their phylogenetic relationships remain mostly unresolved and their classification unstable. We took advantage of the many mitogenomes published in GenBank to produce a new molecular phylogeny of the neogastropods. We completed the taxon sampling by using an in-house bioinformatic pipeline to retrieve mitochondrial genes from 13 transcriptomes, corresponding to five families not represented in GenBank, for a final dataset of 113 taxa. Because mitogenomic data are prone to reconstruction artefacts, eight different evolutionary models were applied to reconstruct phylogenetic trees with IQTREE, RAxML and MrBayes. If the over-parametrization of some models produced trees with aberrant internal long branches, the global topology of the trees remained stable over models and softwares, and several relationships were revealed or found supported here for the first time. However, even if our dataset encompasses 60% of the valid families of neogastropods, some key taxa are missing and should be added in the future before proposing a revision of the classification of the neogastropods. Our study also demonstrates that even complex models struggle to satisfactorily handle the evolutionary history of mitogenomes, still leading to long-branch attractions in phylogenetic trees. Other approaches, such as reduced-genome strategies, must be envisaged to fully resolve the neogastropod phylogeny.
| S-EPMC9544082 | biostudies-literature
Project description:BackgroundMany molluscan species exhibit a high degree of shell morphological plasticity in their shape (including sculptures), size and colour patterns, which can vary significantly depending on environmental conditions. These shell morphological variations make it challenging to differentiate species, based on morphology alone, often resulting in various taxonomic errors, such as misidentifications, overlooking cryptic species diversity or a plethora of nominal species. The genus Siphonaria constitutes a significant component of the macrobenthic invertebrate fauna in intertidal habitats across temperate to tropical regions. Given the limited attention to shell variation in previous taxonomic studies on the Korean Siphonaria species, the extensive range of ecophenotypic shell variations documented in this group raises questions about the taxonomic validity of previously reported Siphonaria species in Korea.New informationThe present study provides a comprehensive taxonomic review of Korean Siphonaria species using a combination of shell morphology, radula structure and phylogenetic analysis of the mtDNA cox1 sequences. This integrative analysis confirmed the validity of S.acmaeoides, S.japonica and S.sirius in Korea, highlighting differences in shell and siphonal groove morphology amongst these species. Detailed descriptions of shell and radula characteristics, along with mtDNA cox1 sequences as DNA barcodes, are also provided, which are very useful for the accurate identification of Siphonaria species. Unlike these three Siphonaria species, the taxonomic validity of the four other species (S.coreensis, S.javanica, S.laciniosa and S.rucuana) previously reported from Korean waters is questionable, given their documented geographic distribution ranges and the potential misidentification of shell variants in Korean malacofaunal studies.
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Project description:Littorina Férussac, 1822 is an abundant genus of small gastropods found in the upper littoral zone of rocky seashores worldwide. Although ecologically important, shell-based species identification in this genus is challenging due to phenotypic variation in shell morphology and lack of diagnostic characters among morphologically similar species. In this study, we revised the taxonomy of Korean Littorina species using morphological characters (shell and radula) and cox1 mitochondrial DNA sequences for three Korean species: L. brevicula, L. sitkana, and L. horikawai. Results suggest that L. sitkana was erroneously reported as L. kasatka in a previous study. A new record for Littorina horikawai (Matsubayashi & Habe in Habe, 1979), previously unknown from Korea, is described, which can be distinguished from L. sitkana by the presence of alternating white and brown spiral ribs on each whorl. Comparison of the mtDNA cox1 gene sequences shows very low intraspecific variation even between geographically distant populations. A phylogenetic tree supports a close relationship between L. horikawai and L. sitkana, consistent with earlier phylogenetic studies.
| S-EPMC6282416 | biostudies-literature
Project description:The genera Kernia and Acaulium comprise species commonly isolated from dung, soil, decaying meat and skin of animal. The taxonomy of these fungi has been controversial and relies mainly on morphological criteria. With the aim to clarify the taxonomy and phylogeny of these fungi, we studied all the available ex-type strains of a large set of species by means of morphological and molecular phylogenetic analyses. Phylogenetic analysis of the partial internal transcribed spacer region (ITS) and the partial 28S rDNA (LSU) showed that the genera Kernia and Acaulium were found to be separated in two distinct lineages in Microascaceae. Based on morphological characters and multilocus phylogenetic analysis of the ITS, LSU, translation elongation factor 1α and β-tubulin genes, the species in Kernia and Acaulium were well separated and two new combinations are introduced, i.e. Acaulium peruvianum and Acaulium retardatum, a new species of Kernia is described, namely Kernia anthracina. Descriptions of the phenotypic features and molecular phylogeny for identification are discussed for accepted species in two genera in this study.
| S-EPMC7316793 | biostudies-literature
Project description:A reliable taxonomy, together with more accurate knowledge of the geographical distribution of species, is a fundamental element for the study of biodiversity. Multiple studies on the gastropod family Neritidae record three species of the genus Neritina in the Brazilian Province: Neritina zebra (Bruguière, 1792), Neritina virginea (Linnaeus, 1758), and Neritina meleagris Lamarck, 1822. While N. zebra has a well-established taxonomic status and geographical distribution, the same cannot be said regarding its congeners. A widely cited reference for the group in Brazil considers N. meleagris a junior synonym of N. virginea. Using a molecular approach (phylogenetic, species delimitation, and statistical parsimony network analyses), based on two mitochondrial markers (COI and 16S), this study investigated if N. virginea and N. meleagris are distinct species. The molecular results confirmed the existence of two strongly supported distinct taxonomic entities in the Brazilian Province, which is consistent with the morphological descriptions previously proposed for N. virginea and N. meleagris. These species occur in sympatry in the intertidal sandstone formations of Northeastern Brazil. Despite the great variation in the colour patterns of the shells, the present study reinforced previous observations that allowed the differentiation of these two species based on these patterns. It also emphasized the importance of the separation of these two clades in future studies, especially those conducted in the Brazilian Province, since these species may cohabit.
| S-EPMC6978406 | biostudies-literature
Project description:An amendment to this paper has been published and can be accessed via a link at the top of the paper.
| S-EPMC7483521 | biostudies-literature
Project description:The taxonomy of the synnematous genera Cephalotrichum, Doratomyces and Trichurus, and other related genera Gamsia, Wardomyces and Wardomycopsis, has been controversial and relies mainly on morphological criteria. These are microascaceous saprobic fungi mostly found in air and soil and with a worldwide distribution. In order to clarify their taxonomy and to delineate generic boundaries within the Microascaceae, we studied 57 isolates that include clinical, environmental and all the available ex-type strains of a large set of species by means of morphological, physiological and molecular phylogenetic analyses using DNA sequence data of four loci (the ITS region, and fragments of rDNA LSU, translation elongation factor 1α and β-tubulin). The results demonstrate that Cephalotrichum, Doratomyces and Trichurus are congeneric and the genus Cephalotrichum is accepted here with Echinobotryum as a further synonym. The genera Acaulium and Fairmania, typified by A. albonigrescens and F. singularis, respectively, are distinct from Microascus and Scopulariopsis, Gamsia is distinct from Wardomyces, and Wardomycopsis is confirmed as a separate genus in the Microascaceae. Two new species of Cephalotrichum are described as C. brevistipitatum and C. hinnuleum. Nine new combinations are proposed, i.e. Acaulium acremonium, A. caviariforme, Cephalotrichum asperulum, C. columnare, C. cylindricum, C. dendrocephalum, C. gorgonifer, Gamsia columbina and Wardomyces giganteus. A neotype is designed for C. stemonitis. Lectotypes and epitypes are designated for A. acremonium, A. albonigrescens, C. gorgonifer, C. nanum and W. anomalus. Cephalotrichum cylindricum, C. microsporum, F. singularis and Gamsia columbina are also epitypified with new specimens. Descriptions of the phenotypic features and dichotomous keys for identification are provided for accepted species in the different genera.
| S-EPMC5007882 | biostudies-literature
Project description:BackgroundThe number of species within the Malagasy genus Lepilemur and their phylogenetic relationships is disputed and controversial. In order to establish their evolutionary relationships, a comparative cytogenetic and molecular study was performed. We sequenced the complete mitochondrial cytochrome b gene (1140 bp) from 68 individuals representing all eight sportive lemur species and most major populations, and compared the results with those obtained from cytogenetic studies derived from 99 specimens.ResultsInterspecific genetic variation, diagnostic characters and significantly supported phylogenetic relationships were obtained from the mitochondrial sequence data and are in agreement with cytogenetic information. The results confirm the distinctiveness of Lepilemur ankaranensis, L. dorsalis, L. edwardsi, L. leucopus, L. microdon, L. mustelinus, L. ruficaudatus and L. septentrionalis on species level. Additionally, within L. ruficaudatus large genetic differences were observed among different geographic populations. L. dorsalis from Sahamalaza Peninsula and from the Ambanja/Nosy Be region are paraphyletic, with the latter forming a sister group to L. ankaranensis.ConclusionOur results support the classification of the eight major sportive lemur taxa as independent species. Moreover, our data indicate further cryptic speciation events within L. ruficaudatus and L. dorsalis. Based on molecular data we propose to recognize the sportive lemur populations from north of the Tsiribihina River, south of the Betsiboka River, and from the Sahamalaza Peninsula, as distinct species.
| S-EPMC1397877 | biostudies-literature
Project description: Not available
| S-EPMC10848888 | biostudies-literature