scholarly journals The second known stygomorphic freshwater crab from China, Phasmon typhlops gen. nov. et sp. nov. (Crustacea, Decapoda, Potamidae), diverged at the beginning of the Late Miocene

ZooKeys ◽  
2020 ◽  
Vol 1008 ◽  
pp. 1-15
Author(s):  
Chao Huang ◽  
Shane T. Ahyong ◽  
Hsi-Te Shih

A new genus and new species of blind freshwater cave crab are described from Chongzuo City, Guangxi Zhuang Autonomous Region, China based on morphology and mitochondrial 16S rDNA sequences. The new genus, Phasmongen. nov., is established for P. typhlopssp. nov., which is only the second blind cave crab known from China and East Asia. The combination of a very wide carapace, overall depigmentation, reduced orbits and vestigial unpigmented eyes of Phasmon immediately separates it from all known potamid genera. Molecular divergence estimates based on 16S rDNA suggest that the lineage to which the new genus belongs diverged from other potamids at the beginning of the Late Miocene (10.8 million years ago), much earlier than other Chinese cave crabs.

Zootaxa ◽  
2020 ◽  
Vol 4766 (3) ◽  
pp. 447-456 ◽  
Author(s):  
CHAO HUANG ◽  
SHENG-ZHUO HUANG ◽  
ZHI-XIN SHEN

A new genus and new species of terrestrial freshwater crab, Calcipotamon puglabrum gen. nov. et sp. nov., is described from the limestone forests of Changjiang, Hainan Island, China, based on morphology and mitochondrial 16S rDNA sequences. The new genus is closest to Neotiwaripotamon Dai & Naiyanetr, 1994, and Tiwaripotamon Bott, 1970, but differs in a combination of carapace, third maxilliped, ambulatory leg and male gonopod characters. Molecular analysis shows that the new genus is closely related with but not clustered within other Hainan potamid genera. Notes on the general biology of this new species are also provided. 


Crustaceana ◽  
2020 ◽  
Vol 93 (11-12) ◽  
pp. 1295-1313
Author(s):  
Si-Ying Mao ◽  
Chao Huang

Abstract A new genus new species of freshwater crab and a new Minpotamon Dai & Türkay, 1997 species are described from eastern Guangdong, China, based on morphology and mitochondrial 16S rDNA sequences. The new genus, Teoswamon gen. nov., is established for T. scolasticum sp. nov., which resembles species from several other genera from Guangdong, but its unique combination of carapace, male gonopod and female vulvae characters set it apart from others. Minpotamon kityang sp. nov. is almost identical with Minpotamon nasicum (Dai, Chen, Song, Fan, Lin & Zeng, 1979) externally, but differs drastically in the male gonopod morphology. Molecular analysis supports the current taxonomic treatments. Teoswamon scolasticum sp. nov. forms its own lineage closely related to Huananpotamon Dai & Ng, 1994. Minpotamon kityang sp. nov. clusters with Minpotamon nasicum, but their genetic distance is of an interspecific level.


2007 ◽  
Vol 21 (6) ◽  
pp. 569 ◽  
Author(s):  
Mark B. Schultz ◽  
Sarah A. Smith ◽  
Alastair M. M. Richardson ◽  
Pierre Horwitz ◽  
Keith A. Crandall ◽  
...  

Nucleotide sequence data from the mitochondrial 16S rDNA region were utilised to investigate phylogenetic relationships and species boundaries among Australian freshwater crayfish belonging to the genera Engaeus Erichson, 1846, Geocharax Clark, 1936 and Gramastacus Riek, 1972. Geocharax and Gramastacus were found to be monophyletic genera but one species currently assigned to Engaeus may belong to another genus. Relationships between the three existing genera were not resolved. Analysis of species boundaries within Geocharax suggests that there are an additional two species in this genus, and our analysis of Gramastacus indicates that undescribed populations from central New South Wales may comprise a second species. The data provide at least one instance of a taxon crossing the Great Dividing Range and provide confirmation of previously proposed hypotheses seeking to explain trans-Bass Strait distributions of species.


ZooKeys ◽  
2020 ◽  
Vol 980 ◽  
pp. 1-21
Author(s):  
Zewei Zhang ◽  
Da Pan ◽  
Xiyang Hao ◽  
Hongying Sun

Two new species of potamid crabs, Eosamon daiaesp. nov. and Indochinamon malipoensesp. nov. are described from the Sino-Burmese border, southwestern Yunnan and from the Sino-Vietnamese border, southeastern Yunnan, China. The two new species can be distinguished from their closest congeners by several characters, among which is the form of the first gonopod structures. Molecular analyses based on partial mitochondrial 16S rDNA sequences also support the systematic status of these new taxa.


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