New Species Of Freshwater Crab Research Articles

A new species of freshwater crab genusFrediusPretzmann, 1967 (Crustacea: Brachyura: Pseudothelphusidae) from a naturally isolated orographic forest enclave within the semiarid Caatinga in Ceará, northeastern Brazil

A new species of freshwater crab, Fredius ibiapaba, is described and illustrated from a mid-altitude forested patch in Ipú (Ibiapaba plateau, Ceará, northeastern Brazil), between 635 to 782 m. The new species can be separated from its congeners by the morphology of its first gonopod: proximal half remarkably swollen, sloping abruptly downwards distally to a nearly right-angular shoulder; mesial lobe much smaller than cephalic spine; cephalic lobe moderately developed; auxiliary lobe lip, delimiting field of apical spines, protruded all the way to distal margin of auxiliary lobe. Comparative 16S rDNA sequencing used to infer the phylogenetic placement of Fredius ibiapaba n. sp. revealed that it is the sister taxon of F. reflexifrons, a species which occurs allopatrically in the Amazon and Atlantic basin’s lowlands (<100 m). Fredius ibiapaba n. sp. and F. reflexifrons are highly dependent upon humidity and most probably were once part of an ancestral population living in a wide humid territory. Shrinking humid forests during several dry periods of the Tertiary and Quaternary likely have resulted in the fragmentation of the ancestral humid area and hence of the ancestral crab population. Fredius reflexifrons evolved and spread in a lowland, humid river basin (Amazon and Atlantic basins), whilst F. ibiapaba n. sp. evolved isolated on the top of a humid plateau. The two species are now separated by a vast intervening area occupied by the semiarid Caatinga

A new species of freshwater crab of the genus Qianguimon Huang, 2018 (Decapoda: Brachyura: Potamidae) from Guangxi, Southern China.

A new species of freshwater crab of the genus Qianguimon Huang, 2018, is described from Guangxi Zhuang Autonomous Region, southern China. It can be distinguished from congeners by the following characters: male first gonopods bent inward at about 45° at base of terminal segment, carapace regions distinct and rugged and the female vulva opening inwards and downwards. In addition, molecular evidence derived from the 16S rRNA gene supported the species described in this study as a new species of Qianguimon.

New species of freshwater crab genus Kingsleya Ortmann, 1897 (Decapoda: Brachyura: Pseudothelphusidae) from Piauí, northeastern Brazil

Abstract A new species of freshwater crab, Kingsleya parnaiba n. sp., collected in a tributary stream of the Parnaiba River Basin in Brazil, is described and illustrated. Kingsleya parnaiba n. sp. morphologically resembles Kingsleya attenboroughi Pinheiro and Santana, 2016 and Kingsleya gustavoi Magalhaes, 2005, from which it can be separated by a set of characters of the first gonopod, chelipeds, and female abdomen.

Description of A New Species of Freshwater Crab of the Genus Qianguimon Huang, 2018 (Crustacea: Decapoda: Brachyura: Potamidae) from Yulin, Guangxi, Southern China.

A new species of freshwater crab of the genus Qianguimon Huang, 2018, Q. rongxianense sp. nov., is described from Rong County, Yulin City, Guangxi Zhuang Autonomous region, southern China. This new species resembles its congeners and some species in the genus Yarepotamon Dai & Türkay, 1997, but can be distinguished from these by its combination of the carapace, third maxilliped, male gonopod, female vulvae characters and size. Molecular data derived from the mitochondrial 16S rDNA supports the establishment of the new species, but does not provide further evidence as to its generic placement.

Description of a new species of freshwater crab of the genus rcithelphusa Pati amp; Sudha Devi, 2015 (Decapoda: Brachyura: Gecarcinucidae) from the Western Ghats, Kerala, India.

A new species of the hitherto monotypic gecarcinucid freshwater crab genus, Arcithelphusa Pati Sudha Devi, 2015, is described from the Western Ghats, in the Wayanad district of Kerala, India. Arcithelphusa tumpikkai sp. nov. can be easily distinguished from the only congener, A. cochleariformis Pati Sudha Devi, 2015, mainly by its relatively broader carapace, the presence of a short flagellum on the exopod of the third maxilliped, and the relatively less stout male first gonopod, with a sharply bent and relatively long terminal segment. The diagnosis for Arcithelphusa is emended to include the new species, which can be useful in distinguishing it from the closely related genus Cylindrotelphusa Alcock, 1909. The state of Kerala now has 38 species of gecarcinucid crabs, including the present new species.

Two new species of freshwater crabs of the genus Potamonautes MacLeay, 1838 (Decapoda: Brachyura: Potamonautidae) from the forests of KwaZulu-Natal, South Africa

ABSTRACTRecent taxonomic studies of forest habitats in South Africa have revealed the presence of three new species of freshwater crabs, suggesting that decapod diversity within the indigenous forest biome remain poorly documented. Surveys of the freshwater crabs of north eastern KwaZulu-Natal province produced a number of specimens from Ntendeka Wilderness Area (Ngome forest) and Nkandla and Ngoye forests that proved to belong to two new species following morphological and molecular analysis (mtDNA sequencing of three loci, 12S rRNA, 16S rRNA and COI). Two undescribed species, P. ntendekaensis sp. nov. and P. ngoyensis sp. nov. are described. The divergence time estimation of the new phylogeny for eastern and southern African freshwater crabs is discussed to illuminate biogeographic patterning and to understand factors responsible for cladogenesis.

On a new species of freshwater crab, Indochinamonkhinpyae, from northern Myanmar (Crustacea, Brachyura, Potamidae).

A new species of freshwater crab of the genus Indochinamon Yeo & Ng, 2007 (family Potamidae), is described from highlands north of Myitkyina in Kachin State, Myanmar. Indochinamonkhinpyaesp. n. is distinguished from congeners by its very rugose carapace, broad male pleon and distinctively structured male first gonopod; and is the first potamid species recorded from northern Myanmar.

A new species of Himalayapotamon Pretzmann, 1966 (Crustacea: Brachyura: Potamidae) marking the westernmost distribution of the genus, with notes on its geographical range evolution

ABSTRACTWe describe a new species of freshwater crab, Himalayapotamon robertsianum sp. nov. from Punjab province of Pakistan, based on morphological characters of the carapace and the first gonopod. The new species demarcates the westernmost distribution limit of the genus. Additionally, we analysed partial sequences of the 16S rRNA locus for some species of the genus Himalayapotamon (p-distances, Bayesian phylogenetical inference), indicating that Himalayapotamon separates into an eastern and a western clade. Based on these results, we propose a biogeographical scenario that can explain the occurrence of the genera Himalayapotamon and Potamon within the same river system: we assume an ancestral widespread distribution of Himalayapotamon in the palaeo-Ganges. When drainage rearrangement diverted the western tributaries of the Ganges into the Indus since the latest Miocene, Himalayapotamon diverged into two clades. Consequently, the western clade is now sharing the Indus drainage with Potamon.urn:lsid:zoobank.org:pub:80B52E6C-0120-4669-A6B0-9F0DA5918EE3

A new species of freshwater crab of the genus Teretamon Yeo Ng, 2007 (Decapoda: Brachyura: Potamidae) from Arunachal Pradesh, northeastern India.

A new species of potamid crab of the genus Teretamon Yeo Ng, 2007, is described from Namdapha Tiger Reserve in Changlang district of Arunachal Pradesh, India. The new species, T. kempi n. sp., can be distinguished from its congeners by a distinct combination of carapace and gonopod characters: a relatively high carapace with a bilobed frontal margin; subquadrate sixth abdominal somite with nearly parallel lateral margins; and a relatively small G1 terminal segment with a semicircular to bluntly triangular dorsal flap. All known Teretamon species are compared with the new species, and a key for this genus is provided.

Biodiversity surveys reveal eight new species of freshwater crabs (Decapoda: Brachyura: Potamidae) from Yunnan Province, China.

Yunnan Province is known to host the highest species diversity of the true freshwater crabs in China; 50 species have been recorded from the province by 2017. In 2004, our team conducted a biodiversity survey of the freshwater crabs in Yunnan Province to determine how well the diversity of crabs in the area has been characterized. We collected a total of 25 species, of which nine species proved to be new to science, and eight of which are described here. These include four species of the genus Indochinamon Yeo & Ng, 2007, two species of the genus Potamiscus Alcock, 1909, and one species each of the genera Pararanguna Dai & Chen, 1985, and Parvuspotamon Dai & Bo, 1994. The new species of Pararanguna and Parvuspotamon represent the second species of respective genera, which are here redefined. Detailed comparisons with morphologically allied species are provided. Photographs of the type specimens of their comparative species which are poorly illustrated in the literature are also provided to allow better understanding of their morphology. This study brings the number of the freshwater crabs of Yunnan Province to 58. Since about 13.8% of the number of species (eight out of 58 species) is increased by surveys conducted within a relatively short period, it is most probable that the species diversity of this group is still understudied in Yunnan Province.

Albertine Rift Valley endemics: three new species of freshwater crabs (Brachyura: Potamoidea: Potamonautidae) from Uganda, the Democratic Republic of the Congo, and Rwanda

ABSTARCTThree new species of potamonautid freshwater crabs are described from the Albertine Rift Valley, Eastern Africa. One of the new species is from Bwindi Impenetrable Forest in Uganda, the second is from Lake Kivu in Rwanda, and the third is from the Rwenzori Mountains in the Democratic Republic of the Congo and Uganda. Diagnoses, illustrations and distribution maps are provided for these taxa, and they are compared to similar species from Uganda and elsewhere in East Africa.www.zoobanl.org/urn:lsid:zoobank.org:pub:FC681BD6-6FB2-4A14-B068-89FC3EB26605

A new species of stygobitic freshwater crab of the genus Rodriguezia Bott, 1969 (Crustacea: Decapoda: Trichodactylidae) from Tabasco, Mexico.

A new species of freshwater crab of the family Trichodactylidae, genus Rodriguezia Bott, 1969 is described from Grutas de Agua Blanca in southern Tabasco, Mexico. Rodriguezia is a genus endemic to northern Chiapas and southern Tabasco, distributed over a small area of 70 km. Rodriguezia adani n. sp., the third species of the genus, occurs north of its two congeners, being stygobitic with obvious adaptations to cave life. It can be distinguished from R. villalobosi, an epigean species, by the absence of eyes, lack of pigmentation and elongation of the pereiopods; and from R. mensabak by having less elongated pereiopods relative to carapace breadth, an extremely reduced ocular peduncle, and a smaller adult size.

Redescription of Austrothelphusa wasselli (Bishop, 1963) (Crustacea: Brachyura: Gecarcinucidae), and designation of a new species from the Gilbert River, north Queensland, Australia.

A new species of freshwater crab,Austrothelphusa gilbertensis, is described from Gilbert River Catchment, north-western Queensland. It is morphologically most similar to A. wasselliBishop, 1963, described from the eastward flowing Stewart Drainage Basin, much further to the north-east on Cape York. It differs fromA. wasselliby several morphological characters including, better defined gastro-cardiac carapace grooves, cervical groove relatively deeper, postfrontal lobes more prominent and bearing striated crests, larger and fewer spots on carapace and legs, epibranchial tooth more prominent, walking legs more slender, and G1 more strongly curved. A CO1 genetic divergence of greater than 6% confirms its novel status. Intraspecific CO1 divergence within catchments is also discussed.

Aegla chilota, new species of anomuran freshwater crab from Chiloé Island, western Patagonia

Abstract We describe a new species of freshwater crab, Aegla chilota, from two small streams at Yaldad Bay, in the southern end of Chiloe Island, western Patagonia. The new taxon is distinguished from the remaining Chilean species of Aegla Leach, 1820 by the following morphological diagnostic features: rostrum neatly triangular, short, scarcely surpassing eyes; orbital sinus wide, shallow, limited by tiny extra-orbital spine and wide extra-orbital sinus; carpal lobe prominent, triangular, tipped by at least two coalescent acute conical scales; second abdominal epimeron little produced, armed with acute scale; telson plate roughly pentagonal, with functional median suture. Molecular phylogenetic analyses also support the separation and diagnosis of A. chilota from its sister taxon, A. hueicollensis Jara and Palacios, 1999. The type locality for A. chilota n. sp. is a small river that drains a small hilly portion of the south-eastern coast of Chiloe Island; the other river in which the species was found is isolated from the type locality by the Yaldad Bay into which both rivers drain.

Cantopotamon, A New Genus of Freshwater Crabs from Guangdong, China, with Descriptions of Four New Species (Crustacea: Decapoda: Brachyura: Potamidae).

Chao Huang, Shane T. Ahyong, and Hsi-Te Shih (2017) A new genus and four new species of freshwater crab, Cantopotamon zhuhaiense n. gen., n. sp., C. shangchuanense n. gen., n. sp., C. hengqinense n. gen., n. sp. and C. yangxiense n. gen., n. sp. are described from Guangdong, China, based on morphology and two mitochondrial markers (16S rDNA and cytochrome oxidase subunit I). Species of Cantopotamon closely resemble species of Yarepotamon Dai & Türkay, 1997, but differ by the combination of carapace, third maxilliped, male pleon, male first gonopod and female vulva characters. Molecular data derived from the mitochondrial 16S rDNA also supports the establishment of the new genus.

Teretamon spelaeum, a new species of freshwater crab (Crustacea: Decapoda: Potamidae) from a limestone cave in Meghalaya, India.

A new species of freshwater crab of the genus Teretamon Yeo Ng, 2007 is described based on material collected from a limestone cave state of Meghalaya, in the northeastern Himalayan region of India. Teretamon spelaeum n. sp. can easily be distinguished from its congeners by a well suite of carapace and gonopod characters: a relatively wider carapace, setose chelipeds and legs, a highly reduced cornea of the eye, and a diagnostic male first gonopod that has a low rounded median dorsal flap on the terminal joint. The morphology of the new species is clearly adapted for the cave dwelling and is the first true troglobitic freshwater crab known from India.

Himalayapotamon chambaensis, a new species of freshwater crab (Crustacea: Brachyura: Potamidae) from Himachal Pradesh, India

A new species of freshwater crab of the genus Himalayapotamon Pretzmann, 1966, is described based on specimens collected from various localities in Chamba District in Himachal Pradesh state, northern India. Himalayapotamon chambaensis n. sp. can be distinguished from congeners by several carapace and gonopod characters: a short median longitudinal granular ridge behind the frontal margin which reaches to the epigastric regions, the terminal segment of the male first gonopod is long and distinctly bent outwards, and the male second gonopod has a long and distally coiled distal segment. An identification key to all the 12 species in the genus is provided.

Two new species of freshwater crabs of the genus Tiwaripotamon Bott, 1970 (Crustacea, Decapoda, Brachyura, Potamidae) from northern Vietnam

Two new species of freshwater crabs of the genus Tiwaripotamon Bott, 1970 (Crustacea, Decapoda, Brachyura, Potamidae) from northern Vietnam

Potamonautes nheenae, a new species of freshwater crab from Gabon, Central Africa, with a description of the first known male of Erimetopus brazzae (A. Milne-Edwards, 1886) from the Democratic Republic of the Congo, Central Africa (Brachyura: Potamoidea: Potamonautidae)

A new species of the freshwater crab genus Potamonautes MacLeay, 1838, is described from Ivindo National Park in Sofala Province, Gabon, Central Africa. Potamonautes nheenae n. sp. is morphologically distinct from the other species of this genus found in Gabon and nearby countries in Central Africa, and is most closely related to P. paecilei (A. Milne-Edwards, 1886) from the Lower Congo River basin in the Democratic Republic of the Congo. The new species is recognised by a unique combination of morphological characters of the adult male first gonopod, anterior sternum, mouthparts, and major cheliped. Illustrations of P. nheenae n. sp. are provided and differences with congeners found in Central Africa are discussed. In addition, the male gonopods, pleon, and sternum of the unusual freshwater crab Erimetopus brazzae (A. Milne-Edwards, 1886), are illustrated for the first time since its description in 1886, following the discovery of the first known male specimen of this species in the collection of the Museum of Comparative Zoology at Harvard University.

A new genus and new species of freshwater crab (Decapoda: Brachyura: Potamidae Ortmann, 1896) from Yunnan Province, China

A new genus Arquatopotamon gen. n. of the family Potamidae Ortmann, 1896, is established and a new species, Arquatopotamon jizushanense sp. n. from Yunnan Province, China is described. The new genus is established based on the distinctive distal part of the male first gonopod, with arched-shaped subterminal and terminal segments (in mesioventral view) and female gonopores (vulvae) on thoracic sternites 5/6 and a combination of characters including the carapace and male telson, while it is similar to the five known genera in Yunnan Province and adjacent area, Tenuipotamon Dai, 1990, Pararanguna Dai &amp; Chen, 1985, Trichopotamon Dai &amp; Chen, 1985, Potamiscus Alcock, 1909 and Aparapotamon Dai &amp; Chen, 1985, in having a third maxilliped exopod without a flagellum. Present molecular data based on a barcoding marker of 16S rDNA provide strong support for the genus as being new.