The freshwater Brachyura (Decapoda: Potamidae, Gecarcinucidae, Sesarmidae) of the Anambas and Natuna Islands, Kepulauan Riau Province, Indonesia. Issue 2 (26th April 2023)

• Record Type: Journal Article
• Authors: Ng, Peter K L; Wowor, Daisy; Yeo, Darren C J
• Is Part Of: Journal of crustacean biology. Volume 43:Issue 2(2023)
• Publication Date: 2023-04-26
• Subjects: biogeography -- Crustacea -- freshwater crabs -- new genus -- Riau Archipelago -- Southeast Asia -- taxonomy; Crustacea -- Periodicals; Crustacés -- Périodiques; Crustacea; Periodicals; 595.305
• DOI: 10.1093/jcbiol/ruad012
• Languages: English
• ISSNs: 0278-0372

Abstract

Abstract: We report on the freshwater crabs of the families Potamidae, Gecarcinucidae, and Sesarmidae in the archipelago of Anambas and Natuna Islands in Indonesia. Five genera (one new) and eight species (four new) are now recorded from the islands. For the Potamidae, a new genus and a new species, Natunamon indonesicum n. sp., is described from Natuna; the taxon has diagnostic characters intermediate between Isolapotamon Bott, 1968 and Ibanum Ng, 1995 from Borneo. A new species of Isolapotamon, I. remotum n. sp., is also described from Anambas; this is the first record of the genus outside Borneo and Mindanao, Philippines. For the Gecarcinucidae, the rare Balssiathelphusa natunaensis Bott, 1970 is collected for the first time since its description, although the type was collected over 120 years ago; the species is redescribed in detail and the composition of the genus discussed. The widely distributed gecarcinucid, Parathelphusa maculata De Man, 1879 is also recorded from Anambas and Natuna. Four species of Sesarmidae are reported: Geosesarma insulare Ng, 1986 (from Anambas), G. teschi Ng, 1986 (from Natuna), G. anambas n. sp. (from Anambas) and G. hashimi n. sp. (from Natuna). Geosesarma hashimi n. sp. is an arboreal species with a suite of atypical characters that suggest its present classification in Geosesarma needs to be reassessed.