Marin I.N.1,2*, Nguyễn Thịnh Văn2 2026. Potamid crabs (Decapoda: Potamidae) from the Cát Tiên National Park with a description of a new species of the genus Dacuomon Ng et Ngo, 2023 // Arthropoda Selecta. Vol.35. No.2: 205–219 [in English].
1 A.N. Severtsov Institute of Ecology and Evolution of the RAS, Leninsky Prosp. 33, Moscow 119071 Russia.
2 Southern Branch of Joint Vietnam-Russia Tropical Science and Technology Research Center, 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.35.2.07
ABSTRACT. The article describes three species of potamid crabs (Crustacea: Decapoda: Potamidae), one of which is new to science, found in the lowland monsoon tropical forest of the Cát Tiên National Park located in Đồng Nai Province of southern Vietnam. All species are recorded from the park area for the first time, as well as differ clearly in their ecological niches and inhabiting biotopes. Neolarnaudia phymatodes (Kemp, 1923) and N. botti Türkay et Naiyanetr, 1987 are completely freshwater aquatic (riverine) species that inhabits rivers and streams, digging their burrows in the riverbank and, probably never leave them. Neolarnaudia phymatodes lives in the fast-flowing streams of the limestone Tà Lài hills, whereas N. botti was found in the low-flowing streams of the lowland monsoon forest. At the same time, Dacuamon cattienensis sp.n. is a terrestrial species that lives on the forest floor, digging burrows in dry forest soil and, probably, rarely descends into rivers or streams. From the single known species of the genus Dacuomon, D. quynhi Ng et Ngo, 2023 described from Dong Xuan district, Phu Yên Province in central Vietnam, Dacuamon cattienensis sp.n. can be separated by more rounded carapace with more convex anterolateral margins (especially in males), less setose third maxilliped with bluntly produced anteroexternal angle of meral segment, less curved terminal segment of G1, smooth thoracic sternites 2 and 3 and telson with concave lateral margins. The type locality of N. botti, indicated on the museum label of the type material as “Mois-Chero, Nord de la Cochinchine”, is discussed in the article, suggesting that it refer to the middle reaches of the Đồng Nai River. Barcoding (partial COI mtDNA gene marker) data is presented for all three potamid crab species for the first time.
KEY WORDS. Crustacea, Brachyura, diversity, lowland monsoon forest, Asia, Indochina.