scholarly journals Molecular and morphological systematics of Bursatella leachii de Blainville, 1817 and Stylocheilus striatus Quoy & Gaimard, 1832 reveal cryptic diversity in pantropically distributed taxa (Mollusca : Gastropoda : Heterobranchia)

2020 ◽  
Author(s):  
Enrico Bazzicalupo ◽  
Fabio Crocetta ◽  
Terrence M. Gosliner ◽  
Véronique Berteaux-Lecellier ◽  
Yolanda E. Camacho-García ◽  
...  
Keyword(s):  
Nominal Species ◽  
Western Pacific Ocean ◽  
Cryptic Diversity ◽  
Western Atlantic ◽  
Sea Hare ◽  
Species Complexes ◽  
Sea Slugs ◽  
Bursatella Leachii ◽  
Pacific Species ◽  
Stylocheilus Striatus

The ragged sea hare (Bursatella leachii) and the long-tailed sea hare (Stylocheilus striatus) are two widely distributed species of benthic heterobranch sea slugs. In this paper, integrative taxonomic analyses have been conducted to detect possible cryptic diversity. Our results revealed that both nominal species are actually species complexes, consisting of five genetically distinct taxa. Two of them belong to the genus Bursatella and three to the genus Stylocheilus. The name B. leachii is retained for a widely distributed species, present in the Atlantic, the Mediterranean, and parts of the Indo-Pacific region. The name B. ocelligera is resurrected for the other species, restricted to the Indo-Pacific and co-occurring with B. leachii in that area. With the present data, it is not possible to test whether B. leachii and B. ocelligera have evolved allopatrically in the Atlantic and Indo-Pacific or sympatrically in the latter. Bursatella leachii has been able to maintain gene flow between the Atlantic and the Indo-Pacific Oceans, possibly because of a combined effect of the Agulhas Leakage process and the ability to survive the colder waters of South Africa. On the contrary, the three species of Stylocheilus are allopatric; the name S. striatus is retained for an Indo-Pacific species, while the names S. polyomma and S. rickettsi are resurrected for species inhabiting the Western Atlantic and the Eastern Pacific respectively. Finally, the discovery of a museum specimen mistakenly identified as B. leachii, but bearing a shell in its adult form, led to the resurrection of the genus Phycophila, previously synonymised with Aplysia. Phycophila euchlora, the only species described to date, is distributed in the Central and Western Pacific Ocean.

Revision of the family Euryplacidae Stimpson, 1871 (Crustacea: Decapoda: Brachyura: Goneplacoidea)

Zootaxa ◽  
2010 ◽  
Vol 2375 (1) ◽  
pp. 1 ◽  
Author(s):  
PETER CASTRO ◽  
PETER K. L. NG
Keyword(s):  
Florida Keys ◽  
Eastern Pacific ◽  
Nominal Species ◽  
Pacific Region ◽  
Tropical Eastern Pacific ◽  
Atlantic Region ◽  
Western Atlantic ◽  
The Family ◽  
The World ◽  
Pacific Species

The family Euryplacidae Stimpson, 1871, traditionally included in the Goneplacidae MacLeay, 1838, is revised based on the examination of the type material of many of its species as well as unidentified and previously identified material from around the world. The revised family now consists of 31 species (including five that are described as new) belonging to 13 genera (including four that are described as new): Eucrate De Haan, 1835, with eight species, of which one is new; Euryplax Stimpson, 1859, with two species; Frevillea A. Milne-Edwards, 1880, with three species; Henicoplax n. gen., with five species of which three are new; Heteroplax Stimpson, 1858, monotypic; Machaerus Leach, 1818, with two species; Nancyplax Lemaitre, García-Gómez, von Sternberg & Campos, 2001, monotypic; Platyozius Borradaile, 1902, monotypic; Psopheticoides Sakai, 1969, monotypic; Systroplax n. gen., monotypic; Trissoplax n. gen., with two species, of which one is new; Trizocarcinus Rathbun, 1914, with two species; Villoplax n. gen., monotypic; and Xenocrate Ng & Castro, 2007, monotypic. The genus Platyozius and Eucrate formosensis Sakai, 1974, are removed from the synonymy of Eucrate and E. alcocki Serène, in Serène & Lohavanijaya, 1973, respectively. Neotypes are selected for Heteroplax dentata Stimpson, 1858, and Pilumnoplax sulcatifrons Stimpson, 1858, two species described from Hong Kong that have a confusing taxonomic history. A neotype is also selected for Euryplax nitida Stimpson, 1859, described from the Florida Keys. Seven nominal species described by other authors were found to be junior subjective synonyms for other species: Eucrate affinis Haswell, 1882, E. costata Yang & Sun 1979, E. haswelli Campbell 1969, and Pseudorhombila sulcatifrons var. australiensis Miers, 1884, of Trissoplax dentata (Stimpson, 1858); Galene laevimanus (Lucas, in Jacquinot & Lucas, 1853) of Eucrate dorsalis (White, 1849); Heteroplax nagasakiensis Sakai, 1934, of H. transversa Stimpson, 1858; and Pilumnoplax sulcatifrons Stimpson, 1858, of Eucrate crenata (De Haan, 1835). Eight euryplacid genera are exclusively found in the Indo-West Pacific region (except one species introduced in the Mediterranean), one is exclusive to each the Eastern Atlantic and Tropical Eastern Pacific regions, three to the Western Atlantic region, and one genus has both Western Atlantic and Tropical Eastern Pacific species.

scholarly journals Cryptic diversity in vertebrates: molecular data double estimates of species diversity in a radiation of Australian lizards ( Diplodactylus , Gekkota)

2009 ◽  
Vol 276 (1664) ◽  
pp. 2001-2007 ◽  
Author(s):  
Paul M. Oliver ◽  
Mark Adams ◽  
Michael S.Y. Lee ◽  
Mark N. Hutchinson ◽  
Paul Doughty
Keyword(s):  
Species Diversity ◽  
Molecular Data ◽  
Nominal Species ◽  
Cryptic Diversity ◽  
Industrialized Countries ◽  
Taxonomic Impediment ◽  
Species Complexes ◽  
Developed Nations ◽  
Diversity Estimates ◽  
Conservation And Management

A major problem for biodiversity conservation and management is that a significant portion of species diversity remains undocumented (the ‘taxonomic impediment’). This problem is widely acknowledged to be dire among invertebrates and in developing countries; here, we demonstrate that it can be acute even in conspicuous animals (reptiles) and in developed nations (Australia). A survey of mtDNA, allozyme and chromosomal variation in the Australian gecko, genus Diplodactylus , increases overall species diversity estimates from 13 to 29. Four nominal species each actually represent multi-species complexes; three of these species complexes are not even monophyletic. The high proportion of cryptic species discovered emphasizes the importance of continuing detailed assessments of species diversity, even in apparently well-known taxa from industrialized countries.

On the presence of Anchistioides willeyi (Borradaile, 1899) (Decapoda: Caridea: Anchistioididae) in the Red Sea

Zootaxa ◽  
2009 ◽  
Vol 2243 (1) ◽  
pp. 53-56 ◽  
Author(s):  
IVAN MARIN
Keyword(s):  
Red Sea ◽  
Type Species ◽  
Specific Form ◽  
The Other ◽  
Valid Species ◽  
Caribbean Region ◽  
Western Atlantic ◽  
Abdominal Somite ◽  
Single Genus ◽  
Pacific Species

The palaemonoid family Anchistioididae Borradaile, 1915 includes a single genus Anchistioides Paulson, 1875 with four known valid species: Anchistioides compressus Paulson, 1875 (type species), A. willeyi (Borradaile, 1899), A. australiensis (Balss, 1921) and A. antiguensis (Schmitt, 1924). Borradaile (1915) suggested two more species within the genus Amphipalaemon Nobili, 1901 (a junior synonym of Anchisitioides Paulson), Amphipalaemon gardineri Borradaile, 1915 (= Anchistioides gardineri) and Amphipalaemon cooperi Borradaile, 1915 (= Anchistioides cooperi) which were later synonomyzed with Anchisitioides willeyi by Gordon (1935), who also suggested their conspecificity with Anchistioides australiensis. At the present time, Anchistioides australiensis is a valid species (Bruce, 1971; Chace & Bruce, 1993) based on specific morphological features such as the presence of sharp postorbital tooth, oblique distal lamela of scaphocerite and sharply produced spines on posterodorsal angles of sixth abdominal somite (see Bruce, 1971: fig. 9). The other Indo-Pacific species, Anchistioides compressus and A. willeyi, can be clearly identified by specific form of scaphocerite, the presence of a well marked blunt postorbital tubercle in A. willeyi which is absent in A. compressus (e.g., Bruce, 1971) and the number of ventral rostral teeth (3-4 large ventral rostral teeth present in A. willeyi while up to 8 small ventral rostral teeth in A. compressus (Paulson, 1875; Gordon, 1935)). Anchistioides antiguensis is clearly separated geographically being known only from the tropical Western Atlantic and Caribbean region (Schmitt, 1924; Holthuis, 1951; Wheeler & Brown, 1968; Martinez-Iglesias, 1986; Markham et al, 1990; Ramos-Porto et al, 1998; Cardoso, 2006).

Patterns of morphological diversity among and within arcid bivalve species pairs separated by the Isthmus of Panama

2001 ◽  
Vol 75 (3) ◽  
pp. 590-606 ◽  
Author(s):  
Peter B. Marko ◽  
Jeremy B. C. Jackson
Keyword(s):  
Morphological Variation ◽  
Fossil Record ◽  
Eastern Pacific ◽  
Nominal Species ◽  
Western Atlantic ◽  
Isthmus Of Panama ◽  
Species Pairs ◽  
Recent Species ◽  
Discriminant Analyses ◽  
Collection Sites

Geminate species are morphologically similar sister-species found on either side of the Isthmus of Panama. The existence of all geminates in the tropical Eastern Pacific ocean and the Caribbean Sea is most often explained by vicariance: closure of the Central American Seaway 3.1 to 3.5 Ma simultaneously isolated populations of species with amphi-American distributions. In this paper, we test the potential of morphological measurements for discriminating between Recent geminate species pairs from three genera (Arca, Arcopsis, and Barbatia) in the bivalve family Arcidae and examine the prospects for distinguishing nominal species in the fossil record. Fourteen morphological variables were used to characterize shell shape and multivariate methods were used to discriminate between five Recent species pairs. Collection sites were also used as a priori groups for discrimination to describe patterns of intraspecific morphological variation and to evaluate differences among samples from different geographic regions.On average, 84 percent of specimens within geminate pairs are classified correctly following five separate discriminant analyses with nominal species as the grouping variable. Although all but one arcid species pair are discriminated with high statistical significance, some collection sites within species are highly morphologically distinct. Overall, a large proportion of specimens from each collection locality (79 percent on average) can be classified correctly to site although no single site possessed a multivariate centroid that was significantly different from all other conspecific centroids. The distinctiveness of some collection sites, however, raises the possibility that some nominal species may harbor cryptic species, indicating the need for wider geographic surveys of both molecular and morphological variation within geminate species pairs.The eigenvalue coefficients derived from the Recent samples of one geminate pair (Arca mutabilis and A. imbricata) were used to assess the potential for identifying arcid species in the fossil record. Discriminant analyses of fossil Arca indicate that the forms that characterize Recent A. mutabilis and A. imbricata are present in the fossil record as far back as the Late Early Miocene, in the Cantaure Formation of Venezuela. Because a deep water connection between the Eastern Pacific and Western Atlantic existed until the Middle Miocene, the morphological differences associated with Recent A. mutabilis and A. imbricata likely existed well before the rising Isthmus affected ocean circulation patterns in tropical America. Therefore, despite great overall morphological similarity, these putative geminate species likely have a time of divergence that is at least four times older than final seaway closure. The geographic distribution of fossils also suggests that morphological forms associated with each Recent species had amphi-American distributions both before and after isthmus formation but are now geographically restricted to either side of the isthmus in the Recent fauna.

Cryptic diversity in non-geniculate coralline algae: a new genus Roseolithon (Hapalidiales, Rhodophyta) and seven new species from the Western Atlantic

2021 ◽  
pp. 1-24
Author(s):  
Luana Miranda Coutinho ◽  
Fernanda Penelas Gomes ◽  
Marina Nasri Sissini ◽  
Talita Vieira-Pinto ◽  
Maria Carolina Muller de Oliveira Henriques ◽  
...  
Keyword(s):  
New Species ◽  
New Genus ◽  
Coralline Algae ◽  
Cryptic Diversity ◽  
Western Atlantic

A Review of the Morid Fish Genus Halargyreus with First Records from the Western North Atlantic

1968 ◽  
Vol 25 (5) ◽  
pp. 877-901 ◽  
Author(s):  
Wilfred Templeman
Keyword(s):  
New Zealand ◽  
North Atlantic ◽  
The Other ◽  
Nominal Species ◽  
Meristic Characters ◽  
Western Atlantic ◽  
North Central ◽  
Northeast Atlantic ◽  
The North

Three specimens of Halargyreus johnsonii taken on the southwestern and southeastern slopes of the Grand Bank in 1959 and 1964 are apparently the first records of this species and genus from the western Atlantic. These specimens are compared with the holotypes of H. johnsonii Günther and of H. brevipes Vaillant and with the syntypes of H. affinis Collett and also with specimens identified as H. affinis from the north-central and northeast Atlantic and with specimens of H. johnsonii from Madeira and New Zealand. These three nominal species are also compared. Is it concluded that for the present all North Atlantic specimens may be referred to H. johnsonii and that the other two species names should be considered as junior synonyms of H. johnsonii.The New Zealand specimens of Halargyreus, described by Günther (1887, Challenger Rept., 22(Zoology), p. 1–268) as H. johnsonii, have higher numbers for some meristic characters than Atlantic specimens of H. johnsonii but these differences are not too great to be possibly due to environmental differences. Pending the study of additional specimens in better condition, these New Zealand specimens are tentatively allowed to remain as H. johnsonii.

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.

A review of the genus Platyrhina (Chondrichthys: Platyrhinidae) from the northwestern Pacific, with descriptions of two new species

Zootaxa ◽  
2011 ◽  
Vol 2738 (1) ◽  
pp. 26 ◽  
Author(s):  
YUKIO IWATSUKI ◽  
KEI MIYAMOTO ◽  
KAZUHIRO NAKAYA ◽  
JIE ZHANG
Keyword(s):  
New Species ◽  
Pacific Coast ◽  
Northwestern Pacific ◽  
Nominal Species ◽  
Undescribed Species ◽  
White Pigment ◽  
Light Yellow ◽  
The Pacific ◽  
Two New Species ◽  
Pacific Species

The genus Platyrhina from the northwestern Pacific was reviewed, including a redescription and neotype proposal for Platyrhina sinensis (Bloch and Schneider 1801), and the description of two new species. Platyrhina limboonkengi Tang 1933 is relegated to the synonymy of P. sinensis, both species having two rows of hooked thorns on the mid-dorsum of the tail. Specimens previously widely identified as P. sinensis, but characterized by one row of such hooked thorns, represented an undescribed species, herein named Platyrhina tangi Iwatsuki, Zhang and Nakaya sp. nov. Platyrhina hyugaensis Iwatsuki, Miyamoto and Nakaya sp. nov., known from specimens limited primarily to the Hyuga Nada Sea, off Miyazaki, the Pacific coast of southern Japan, is similar to P. tangi in having one row of hooked thorns on the mid-dorsum of the trunk and tail, but differs in having larger hooked thorns, not encircled by light yellow or white pigment on the orbital, nape and scapular regions, and a pair of hooked thorns (absent in P. tangi) anteriorly on the scapular region. Nominal species are discussed and key to northwestern Pacific species of Platyrhina is provided.

Molecular divergence between two sympatric species of Dondice (Mollusca: Nudibranchia) with distinct feeding specializations

2013 ◽  
Vol 93 (7) ◽  
pp. 1887-1893 ◽  
Author(s):  
Luis Gonzalez ◽  
Dieta Hanson ◽  
Ángel Valdés
Keyword(s):  
Feeding Habits ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Sympatric Species ◽  
Developmental Differences ◽  
Nominal Species ◽  
Western Atlantic ◽  
16S Gene ◽  
Putative Species ◽  
Gene Data

Analysis of mitochondrial (16S) and nuclear (H3) gene data using phylogenetic and population genetic approaches has revealed some genetic differences between two putative species of western Atlantic Dondice opisthobranchs that feed differentially on hydroids or on up-side-down jellies of the genus Cassiopeia. These results partially support the validity of the species Dondice parguerensis, which was described for the jelly-eating Dondice. However, phylogenetic analyses revealed that the hydroid-feeding species Dondice occidentalis and D. parguerensis are not reciprocally monophyletic and they are identical for the nuclear H3 gene. Although there are morphological and developmental differences between these two nominal species, the molecular data are inconclusive. A possible explanation is that the two putative species are in the process of speciation due to different feeding habits, resulting in the presence of genetic synapomorphies in D. parguerensis, but only in the more variable 16S gene. Because the ranges D. occidentalis and D. parguerensis overlap and there are no obvious barriers to gene flow between the two putative species, this may constitute a possible example of incipient sympatric speciation in benthic marine organisms.

Extensive cryptic diversity of giant clams (Cardiidae: Tridacninae) revealed by DNA-sequence-based species delimitation approaches with new data from Hainan Island, South China Sea

2020 ◽  
Vol 86 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Jun Liu ◽  
Dan Cui ◽  
Hui Wang ◽  
Jiawei Chen ◽  
Helu Liu ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Species Delimitation ◽  
Strong Support ◽  
Hainan Island ◽  
The Philippines ◽  
Nominal Species ◽  
Cryptic Diversity ◽  
China Sea ◽  
Giant Clams

Abstract Accurate species delimitation is important, especially for endangered species. As one of the most conspicuous bivalve taxa, giant clams are threatened throughout their geographic range. Many phylogeographic studies have revealed strong population structure among giant clams in the Indo-Pacific, suggesting cryptic diversity within these species. However, less attention has been paid to their identification and delimitation. In this study, we assembled a comprehensive dataset of mitochondrial cytochrome c oxidase subunit I (COI) sequences for Tridacna species, focusing on new sequences from Hainan Island in the South China Sea and previously published ones from Japan, Taiwan, Singapore, the Philippines, Indonesia, Australia, the Solomon Islands and the Red Sea. Three nominal species, Tridacna crocea, T. squamosa and T. noae, were recognized at Hainan Island on the basis of distance-based DNA barcoding, with mean interspecific K2P distances of 10.6–24.7% for seven Tridacna species (T. crocea, T. squamosa, T. noae, T. maxima, T. mbalavuana, T. derasa and T. gigas). The most abundant species, T. noae, represents the first record of this species from Hainan Island. Using a combination of phylogenetic and DNA-based species delimitation analyses (automatic barcode gap discovery, generalized mixed Yule coalescent and Bayesian Poisson tree processes), we found strong support for a total of 13 operational taxonomic units (OTUs) for the seven nominal Tridacna species. These results, coupled with the fact that each OTU occupies different regions in the Indo-Pacific, strongly suggest multiple cryptic species of giant clams. Our findings point to the need for taxonomic revisionary work on giant clams throughout the Indo-Pacific; such work will have important conservation implications.

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