Marin I.N.1,2*, Nguyễn Thịnh Văn2. 2026. A new species of the potamid genus Eosamon Yeo et Ng, 2007 from Bảy Núi mountainous hills, southern Vietnam // Arthropoda Selecta. Vol.35. No.1: 70–78 [in English].
1 A.N. Severtsov Institute of Ecology and Evolution of the RAS, Moscow Russia.
2 Southern Branch of Joint Vietnam–Russia Tropical Science and Technology Research Centre, Ho Chi Minh City, Vietnam.
*corresponding author
Ivan Marin: coralliodecapoda@mail.ru https://orcid.org/0000-0003-0552-8456
Thịnh Văn Nguyễn thinh39b@gmail.com https://orcid.org/0000-0002-5376-830X
doi: 10.15298/arthsel.35.1.08
ABSTRACT. A new species of the potamid crab genus Eosamon Yeo et Ng, 2007 (Crustacea: Decapoda: Potamidae), Eosamon baynuiensis sp.n., is described from Bảy Núi (10°29′N 104°59′E), a range of small mountainous hills located in the Tri Tôn and Tịnh Biên districts of An Giang Province, southern Vietnam. The new species morphologically closely resembles two other Eosamon species known from southern Vietnam, Eosamon brousmichei (Rathbun, 1904) and Eosamon nominathuis Yeo, 2010, but can be distinguished by the shape and proportions of the carapace and terminal segment of G1. Since these crabs live on mountainous hills that are currently isolated within the delta and were once “islands” when sea level was higher, we see the evolution of these species as an example of allopatric (island) speciation. The detailed taxonomy of all described representatives of the genus Eosamon from southern Vietnam is discussed in the article.
KEY WORDS: diversity, Brachyura, Potamidae, Eosamon, taxonomy, SE Asia, Vietnam, barcoding.