scholarly journals A glimpse in the dark? A first phylogenetic approach in a widespread freshwater snail from tropical Asia and northern Australia (Cerithioidea, Thiaridae)

2019 ◽  
Vol 95 (2) ◽  
pp. 373-390 ◽  
Author(s):  
Dusit Boonmekam ◽  
Duangduen Krailas ◽  
France Gimnich ◽  
Marco T. Neiber ◽  
Matthias Glaubrecht
Keyword(s):  
Phylogenetic Analyses ◽  
Molecular Genetic ◽  
Reproductive Mode ◽  
Freshwater Snail ◽  
Shell Morphology ◽  
Integrative Approach ◽  
Nominal Species ◽  
Oriental Region ◽  
Tropical Asia ◽  
Tropical Areas

Thiaridae are a speciose group of freshwater snails in tropical areas including a high number of described nominal taxa for which modern revisions are mostly lacking. Using an integrative approach, the systematic status of a group of thiarids from the Oriental region, including the nominal speciesMelaniaasperaandM.rudis, is reassessed on the basis of shell morphology and biometry, radula dentition patterns, and reproductive biology along with molecular genetic methods. Our results suggest that populations from the Oriental region cannot be distinguished on the basis of shell morphology, radula characters and their reproductive mode and are monophyletic based on mitochondrial sequences. Hence,M.rudiswithM.asperaare regarded as belonging to the same species along with several other nominal taxa that were previously included inM.rudis. Moreover, populations from Thailand and Australia, from where the species was not previously recorded, could be shown to form a monophyletic group together with samples from Indonesia. However, a generic affiliation withThiara, in which the investigated taxa were often included in the past, was not supported in our phylogenetic analyses, highlighting the need for a comprehensive revision of the genus-group systematics of Thiaridae as a whole.

scholarly journals Resurrecting a subgenus to genus: molecular phylogeny ofEuphylliaandFimbriaphyllia(order Scleractinia; family Euphyllidae; clade V)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4074
Author(s):  
Katrina S. Luzon ◽  
Mei-Fang Lin ◽  
Ma. Carmen A. Ablan Lagman ◽  
Wilfredo Roehl Y. Licuanan ◽  
Chaolun Allen Chen
Keyword(s):  
Phylogenetic Analyses ◽  
Reproductive Traits ◽  
Reproductive Mode ◽  
Integrated Approach ◽  
Nominal Species ◽  
Colony Structure ◽  
Skeletal Morphology ◽  
Strong Basis ◽  
Tubulin Genes ◽  
Phylogenetic Resolution

BackgroundThe corallum is crucial in building coral reefs and in diagnosing systematic relationships in the order Scleractinia. However, molecular phylogenetic analyses revealed a paraphyly in a majority of traditional families and genera among Scleractinia showing that other biological attributes of the coral, such as polyp morphology and reproductive traits, are underutilized. Among scleractinian genera, theEuphyllia, with nine nominal species in the Indo-Pacific region, is one of the groups that await phylogenetic resolution. Multiple genetic markers were used to construct the phylogeny of sixEuphylliaspecies, namelyE. ancora, E. divisa, E. glabrescens, E. paraancora, E. paradivisa,andE. yaeyamaensis.The phylogeny guided the inferences on the contributions of the colony structure, polyp morphology, and life history traits to the systematics of the largest genus in Euphyllidae (clade V) and, by extension, to the rest of clade V.ResultsAnalyses of cytochrome oxidase 1 (cox1), cytochrome b (cytb), and β-tubulin genes of 36 colonies representingEuphylliaand a confamilial species,Galaxea fascicularis,reveal two distinct groups in theEuphylliathat originated from different ancestors.Euphyllia glabrescensformed a separate group.Euphyllia ancora, E. divisa, E. paraancora, E. paradivisa,andE. yaeyamaensisclustered together and diverged from the same ancestor asG. fascicularis.The 3′-end of thecox1gene ofEuphylliawas able to distinguish morphospecies.DiscussionSpecies ofEuphylliawere traditionally classified into two subgenera,EuphylliaandFimbriaphyllia,which represented a dichotomy on colony structure. The paraphyletic groups retained the original members of the subgenera providing a strong basis for recognizingFimbriaphylliaas a genus. However, colony structure was found to be a convergent trait betweenEuphylliaandFimbriaphyllia,while polyp shape and length, sexuality, and reproductive mode defined the dichotomy better. Species in a genus are distinguished by combining polyp morphology and colony form. The cluster ofE. glabrescensof theEuphylliagroup is a hermaphroditic brooder with long, tubular tentacles with knob-like tips, and a phaceloid colony structure. TheFimbriaphylliagroup, withF. paraancora, F. paradivisa, F. ancora, F. divisa,andF. yaeyamaensis,are gonochoric broadcast spawners with short polyps, mixed types of tentacle shapes, and a phaceloid or flabello-meandroid skeleton. Soft-tissue morphology ofG. fascicularisandCtenella chagiuswere found to be consistent with the dichotomy.ConclusionsThe paraphyly of the original members of the previous subgenera justify recognizingFimbriaphylliaas a genus. The integrated approach demonstrates that combining polyp features, reproductive traits, and skeletal morphology is of high systematic value not just toEuphylliaandFimbriaphylliabut also to clade V; thus, laying the groundwork for resolving the phylogeny of clade V.

Identifying species of Bythinella (Caenogastropoda: Rissooidea): A plea for an integrative approach

Zootaxa ◽  
2007 ◽  
Vol 1563 (1) ◽  
pp. 1-16 ◽  
Author(s):  
MARTIN HAASE ◽  
THOMAS WILKE ◽  
PAUL MILDNER
Keyword(s):  
Large Scale ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Shell Morphology ◽  
Ice Age ◽  
Integrative Approach ◽  
The South ◽  
Stem Species ◽  
Last Ice Age ◽  
Large Scale Project

The genus Bythinella comprises many species throughout Europe, but species delimitation, traditionally based on shell morphology and genital anatomy, is often a matter of debate. Out of an ongoing large-scale project on the phylogeny of the genus, we analyzed the relationships of species occurring in the south Austrian province Carinthia and in neighboring Slovenia as a model for similar cases of systematic and taxonomic ambiguity. Our analyses based on sequence data of a fragment of COI comprising 638 bp, morphological and anatomical investigations confirmed the presence of three species, B. opaca (Gallenstein, 1848), B. robiciana (Clessin, 1890) and B. angelitae nom. nov. for B. opaca (Frauenfeld, 1857). The latter, while genetically distinct, is morphologically and anatomically cryptic in that it can only be distinguished from B. opaca by the denticulation of the radular marginal teeth. B. robiciana, on the other hand, is morphologically well defined, but genetically not separable from B. opaca, its stem species. Thus, taxonomy in Bythinella has to be based on the integration of morphology, anatomy and genetics. Our phylogenetic analyses suggest that B. opaca has colonized Carinthia, which has largely been covered by glaciers during the last ice age, along two routes, one from the south and a second one from the southeast.

scholarly journals Molecular phylogeography and reproductive biology of the freshwater snail Tarebia granifera in Thailand and Timor (Cerithioidea, Thiaridae): morphological disparity versus genetic diversity

2018 ◽  
Vol 94 (2) ◽  
pp. 461-493 ◽  
Author(s):  
Nuanpan Veeravechsukij ◽  
Duangduen Krailas ◽  
Suluck Namchote ◽  
Benedikt Wiggering ◽  
Marco T. Neiber ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Molecular Genetic ◽  
Shell Morphology ◽  
Water Bodies ◽  
Trematode Species ◽  
Species Differentiation ◽  
Haplotype Networks ◽  
Mtdna Sequence

The freshwater thiarid gastropod Tarebiagranifera (Lamarck, 1816), including taxa considered either congeneric or conspecific by earlier authors, is widespread and abundant in various lentic and lotic water bodies in mainland and insular Southeast Asia, with its range extending onto islands in the Indo-West-Pacific. This snail is, as one of the most frequent and major first intermediate host, an important vector for digenic trematodes causing several human diseases. As a typical thiarid T.granifera is viviparous and parthenogenetic, with various embryonic stages up to larger shelled juveniles developing within the female’s subhemocoelic (i.e non-uterine) brood pouch. Despite the known conchological disparity in other thiarids as well as this taxon, in Thailand Tarebia has been reported with the occurrence of one species only. In light of the polytypic variations found in shell morphology of freshwater snails in general and this taxon in particular, the lack of a modern taxonomic-systematic revision, using molecular genetics, has hampered more detailed insights to date, for example, into the locally varying trematode infection rates found in populations of Tarebia from across its range in Thailand as well as neighboring countries and areas. Here, we integrate evidence from phylogeographical analyses based on phenotypic variation (shell morphology, using biometry and geometric morphometrics) with highly informative and heterogeneous mtDNA sequence data (from the gene fragments cytochrome c oxidase subunit 1 and 16 S rRNA). We evaluate both the morphological and molecular genetic variation (using several phylogenetic analyses, including haplotype networks and a dated molecular tree), in correlation with differences in the reproductive biology among populations of Tarebia from various water bodies in the north, northwest, central, and south of Thailand, supplementing our respective analyses of parasite infections of this thiarid by cercaria of 15 trematode species, reported in a parallel study. Based on the comparison of topotypical material from the island of Timor, with specimens from 12 locations as reference, we found significant, albeit not congruent variation of both phenotype and genotype in Tarebiagranifera, based on 1,154 specimens from 95 Thai samples, representing a geographically wide-ranging, river-based cross-section of this country. Our analyses indicate the existence of two genetically distinct clades and hint at possible species differentiation within what has been traditionally considered as T.granifera. These two lineages started to split about 5 mya, possibly related to marine transgressions forming what became known as biogeographical barrier north of the Isthmus of Kra. Grounded on the site-by-site analysis of individual Tarebia populations, our country-wide chorological approach focussing on the conchologically distinct and genetically diverse lineages of Tarebia allows to discuss questions of this either reflecting subspecific forms versus being distinct species within a narrowly delimited species complex. Our results, therefore, provide the ground for new perspectives on the phylogeography, evolution and parasitology of Thai freshwater gastropods, exemplified here by these highly important thiarids.

A new hip-pocket frog from mid-eastern Australia (Anura: Myobatrachidae: Assa)

Zootaxa ◽  
2021 ◽  
Vol 5057 (4) ◽  
pp. 451-486
Author(s):  
MICHAEL J. MAHONY ◽  
HARRY B. HINES ◽  
STEPHEN V. MAHONY ◽  
BEDE MOSES ◽  
SARAH R. CATALANO ◽  
...  
Keyword(s):  
Genetic Relationships ◽  
Phylogenetic Analyses ◽  
Molecular Genetic ◽  
Nuclear Genome ◽  
Critically Endangered ◽  
Nominal Species ◽  
Nucleotide Polymorphisms ◽  
Conservation Assessment ◽  
Separate Species ◽  
Eastern Australia

The hip-pocket frog (Assa darlingtoni), a small terrestrial myobatrachid frog found in mid-eastern Australia, has a highly derived, unusual, reproductive mode involving a unique form of male parental care. Males have subcutaneous pouches that open near the hip, and the developing tadpoles are carried in these pouches to post metamorphosis. It is found on several isolated mountain ranges in closed forest habitats, associated with high rainfall and temperate or sub-tropical climates. We established genetic relationships among specimens sampled across the range using phylogenetic analyses of thousands of single nucleotide polymorphisms (SNPs) from the nuclear genome and mitochondrial ND2 gene nucleotide sequences. These analyses uncovered two lineages that are genetically distinct in both nDNA and mtDNA analyses and that have low levels of divergence in male advertisement calls and are morphologically cryptic. Our data support separate species status for each lineage, based on the molecular genetic data. The first, which we name as a new species, Assa wollumbin sp. nov., is restricted to a single mountain, Wollumbin (= Mount Warning), the eroded cone of an ancient shield volcano—the Tweed Volcano. The second, the nominal species A. darlingtoni, has a wider distribution in five geographically disjunct subpopulations along 430 km of the Great Dividing Range in south-eastern Queensland and north-eastern New South Wales. The distributions of the two species closely approach within 15 km of each other on the central plug and rim of the caldera of the Tweed Volcano. Assa wollumbin sp. nov. meets the conservation criteria for Critically Endangered [A3(e), B2(a,b)]. When all subpopulations of A. darlingtoni are combined the conservation assessment is Endangered [A3(e), B2(a,b)]. Because of the fragmented nature of the distribution of A. darlingtoni, combined with the genetic evidence of concordant sub-structuring, we also conducted a conservation assessment on the five subpopulations. Two were assessed as Critically Endangered (D’Aguilar Range and Conondale/Blackall Ranges), and the remainder as Endangered (Dorrigo Plateau, McPherson Ranges, and Gibraltar Ranges/Washpool).  

scholarly journals Intraspecific morphological and genetic variability in the European freshwater snail Radix labiata (Rossmaessler, 1835) (Gastropoda: Basommatophora: Lymnaeidae)

2013 ◽  
Vol 82 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Katrin Schniebs ◽  
Glöer Peter ◽  
Maxim V. Vinarski ◽  
Anna K. Hundsdoerfer
Keyword(s):  
Morphological Character ◽  
Mitochondrial Gene ◽  
Intraspecific Variability ◽  
Freshwater Snail ◽  
Morphological Characters ◽  
Shell Morphology ◽  
Integrative Approach ◽  
Bursa Copulatrix ◽  
Gene Fragment ◽  
Cyt B

Radix labiata is a widely distributed Palaearctic freshwater snail. This work aims to improve the knowledge of the intraspecific variability in the most important characters used for its determination. To find out which characters are really suitable to distinguish this species from other similar Radix species an integrative approach was applied, involving morphological and molecular data.Molecular sequences of the nuclear spacer fragment ITS-2 and/or the mitochondrial gene fragment cyt-b were obtained from 26 individuals of R. labiata from different regions of Europe, including type localities of Limnaeus pereger labiatus. From the subsample of 24 specimens of which sequences of both gene fragments were available, the variability of several characters that are commonly used for species identification (shell morphology, mantle pigmentation, shape and position of the bursa copulatrix, length and position of the bursa duct, length ratio of praeputium to penial sheath) were measured or documented. Morphological characters distinguishing R. labiata from R. balthica, R. lagotis and the genus Stagnicola are discussed. The best morphological character to differentiate these species is the position of the bursa and the bursa duct. Mantle pigmentation and the ratio of the length of the praeputium to that of the penial sheath are not useful for differentiating R. labiata and R. balthica. Analysis of the network of haplotypes (cyt-b) revealed no correlation between recognisable clusters and geography amongst the studied specimens.

Systematic status of Campydora Cobb, 1920 (Nematoda: Campydorina)

Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Peter Mullin ◽  
Timothy Harris ◽  
Thomas Powers
Keyword(s):  
Maximum Likelihood ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
Maximum Parsimony ◽  
Phylogenetic Analyses ◽  
Small Subunit ◽  
Systematic Position ◽  
Nominal Species ◽  
Competing Hypotheses ◽  
Small Subunit Ribosomal Dna

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.

A revision of the gobiid fish genus Pseudogobius (Teleostei, Gobiidae, Tridentigerinae), with description of seven new species from Australia and South-east Asia

Zootaxa ◽  
2021 ◽  
Vol 4961 (1) ◽  
pp. 1-85
Author(s):  
HELEN K. LARSON ◽  
MICHAEL P. HAMMER
Keyword(s):  
New Species ◽  
Feedback Loop ◽  
Valid Species ◽  
Nominal Species ◽  
Type Specimens ◽  
Gobiid Fish ◽  
West Pacific ◽  
Close Proximity ◽  
Tropical Areas ◽  
Initial Focus

The tridentigerine genus Pseudogobius is widespread, from temperate to tropical areas of the Indo-west Pacific. A morphological review of the genus was carried out, with the initial focus on South-east Asian and Australian species. There are about 21 nominal species in the genus; however, the type specimens for some nominal species are missing. Our work recognises 15 valid species so far, including seven new species, which are described herein: P. aquilonius n. sp., P. cinctus n. sp., P. eos n. sp., P. hoesei n. sp., P. jeffi n. sp., P. rhizophora n. sp. and P. verticalis n. sp. We also conclude that P. poicilosoma (Bleeker, 1849) is the senior synonym of P. javanicus (Bleeker, 1856). Pseudogobius poicilosoma, P. gastrospilos (Bleeker, 1853) and P. javanicus are accepted here as conspecific, although the types are in poor condition (note that all three names were given to specimens collected within close proximity to each other in coastal Java, Indonesia). A key to valid species is presented. The revision benefited from an adaptive feedback loop with companion genetic analyses, with the most comprehensive data available for the Australian region. Broader preliminary genetic data suggest the potential for recognition of additional cryptic species, with the current study providing a platform for future systematic work. Pseudogobius are a prominent part of estuarine biodiversity in the Indo-west Pacific, and this study helps to highlight the need to better understand the taxonomy and conservation requirements of cryptobenthic fishes. 

scholarly journals Descriptions of four new dextral land snails of the genus Camaena (Gastropoda, Eupulmonata, Camaenidae) from south China

ZooKeys ◽  
2020 ◽  
Vol 996 ◽  
pp. 37-58
Author(s):  
Pei Wang ◽  
Mei-Ling Hu ◽  
Jun-Hong Lin ◽  
Hai-Fang Yang ◽  
Xiao-Jing Li ◽  
...  
Keyword(s):  
New Species ◽  
South China ◽  
Dna Sequences ◽  
Reproductive System ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Land Snails ◽  
Shell Morphology ◽  
Molecular Phylogenetic ◽  
Living Environments

In this study, four new dextral camaenid from China are reported, based on shell morphology, reproductive system anatomy, and molecular phylogenetic analyses: Camaena funingensis Zhou, Wang & Lin, sp. nov., Camaena gaolongensis Zhou, Wang & Lin, sp. nov., Camaena maguanensis Zhou, Wang & Hu, sp. nov., and Camaena yulinensis Zhou, Wang & Hu, sp. nov. Detailed descriptions of the morphological characteristics including shells and genitalia, DNA sequences, and living environments of the four new species are provided, with further comparisons with congeners.

scholarly journals Molecular forms of Anopheles subpictus and Anopheles sundaicus in the Indian subcontinent

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Ankita Sindhania ◽  
Manoj K. Das ◽  
Gunjan Sharma ◽  
Sinnathamby N. Surendran ◽  
B. R. Kaushal ◽  
...  
Keyword(s):  
Sibling Species ◽  
Molecular Form ◽  
Indian Subcontinent ◽  
Phylogenetic Analyses ◽  
Coastal Areas ◽  
Molecular Forms ◽  
Nominal Species ◽  
Anopheles Subpictus ◽  
Species Complexes ◽  
Molecular Phylogenetic

Abstract Background Anopheles subpictus and Anopheles sundaicus are closely related species, each comprising several sibling species. Ambiguities exist in the classification of these two nominal species and the specific status of members of these species complexes. Identifying fixed molecular forms and mapping their spatial distribution will help in resolving the taxonomic ambiguities and understanding their relative epidemiological significance. Methods DNA sequencing of Internal Transcribed Spacer-2 (ITS2), 28S-rDNA (D1-to-D3 domains) and cytochrome oxidase-II (COII) of morphologically identified specimens of two nominal species, An. subpictus sensu lato (s.l.) and An. sundaicus s.l., collected from the Indian subcontinent, was performed and subjected to genetic distance and molecular phylogenetic analyses. Results Molecular characterization of mosquitoes for rDNA revealed the presence of two molecular forms of An. sundaicus s.l. and three molecular forms of An. subpictus s.l. (provisionally designated as Form A, B and C) in the Indian subcontinent. Phylogenetic analyses revealed two distinct clades: (i) subpictus clade, with a single molecular form of An. subpictus (Form A) prevalent in mainland India and Sri Lanka, and (ii) sundaicus clade, comprising of members of Sundaicus Complex, two molecular forms of An. subpictus s.l. (Form B and C), prevalent in coastal areas or islands in Indian subcontinent, and molecular forms of An. subpictus s.l. reported from Thailand and Indonesia. Based on the number of float-ridges on eggs, all An. subpictus molecular Form B were classified as Species B whereas majority (80%) of the molecular Form A were classified as sibling species C. Fixed intragenomic sequence variation in ITS2 with the presence of two haplotypes was found in molecular Form A throughout its distribution. Conclusion A total of three molecular forms of An. subpictus s.l. and two molecular forms of An. sundaicus s.l. were recorded in the Indian subcontinent. Phylogenetically, two forms of An. subpictus s.l. (Form B and C) prevalent in coastal areas or islands in the Indian subcontinent and molecular forms reported from Southeast Asia are members of Sundaicus Complex. Molecular Form A of An. subpictus is distantly related to all other forms and deserve a distinct specific status.

scholarly journals Adaptive divergence in shell morphology in an ongoing gastropod radiation from Lake Malawi

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Bert Van Bocxlaer ◽  
Claudia M. Ortiz-Sepulveda ◽  
Pieter R. Gurdebeke ◽  
Xavier Vekemans
Keyword(s):  
Common Garden ◽  
Shell Morphology ◽  
Model Systems ◽  
Shell Shape ◽  
Adaptive Divergence ◽  
Nominal Species ◽  
Shape Variation ◽  
In The Wild ◽  
Evolutionary Radiations ◽  
Contrasting Habitats

Abstract Background Ecological speciation is a prominent mechanism of diversification but in many evolutionary radiations, particularly in invertebrates, it remains unclear whether supposedly critical ecological traits drove or facilitated diversification. As a result, we lack accurate knowledge on the drivers of diversification for most evolutionary radiations along the tree of life. Freshwater mollusks present an enigmatic example: Putatively adaptive radiations are being described in various families, typically from long-lived lakes, whereas other taxa represent celebrated model systems in the study of ecophenotypic plasticity. Here we examine determinants of shell-shape variation in three nominal species of an ongoing ampullariid radiation in the Malawi Basin (Lanistes nyassanus, L. solidus and Lanistes sp. (ovum-like)) with a common garden experiment and semi-landmark morphometrics. Results We found significant differences in survival and fecundity among these species in contrasting habitats. Morphological differences observed in the wild persisted in our experiments for L. nyassanus versus L. solidus and L. sp. (ovum-like), but differences between L. solidus and L. sp. (ovum-like) disappeared and re-emerged in the F1 and F2 generations, respectively. These results indicate that plasticity occurred, but that it is not solely responsible for the observed differences. Our experiments provide the first unambiguous evidence for genetic divergence in shell morphology in an ongoing freshwater gastropod radiation in association with marked fitness differences among species under controlled habitat conditions. Conclusions Our results indicate that differences in shell morphology among Lanistes species occupying different habitats have an adaptive value. These results also facilitate an accurate reinterpretation of morphological variation in fossil Lanistes radiations, and thus macroevolutionary dynamics. Finally, our work testifies that the shells of freshwater gastropods may retain signatures of adaptation at low taxonomic levels, beyond representing an evolutionary novelty responsible for much of the diversity and disparity in mollusks altogether.

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