Zoological Studies

Vol. 61, 2022

(update: 2022.5.5)

Establishment of A New Bornean Genus of Gecarcinucidae (Crustacea: Brachyura), with Descriptions of Five New Species

Peter K. L. Ng1 and Jongkar Grinang2,*

1Lee Kong Chian Natural History Museum, Faculty of Science, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Republic of Singapore. E-mail: peterng@nus.edu.sg (Ng)
2Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia. *Correspondence: E-mail: gjongkar@unimas.my (Grinang)

Received 13 September 2021 / Accepted 4 February 2022
Communicated by Benny K.K. Chan

The freshwater gecarcinucid species from Borneo previously referred to Sundathelphusa Bott, 1969, are transferred to a new genus. Borneosa gen. nov. can be diagnosed by the presence of a distinct frontal median triangle that is shorter than the frontal margin, a relatively longer male thoracic sternum in which the sternopleonal cavity reaches more anteriorly, and a male first gonopod that has the terminal segment prominently covered with long setae. The eight species recognised—B. tenebrosa (Holthuis, 1979), B. aspera (Ng & Stuebing, 1989), B. brachyphallus (Ng, 2015), and five new species, B. niah, B. bario, B. kapit, B. sarawakensis and B. serrata—can be distinguished by characters of the frontal median triangle, epibranchial tooth, anterolateral margin, third maxillipeds, ambulatory legs, male sternum, male pleon andmale first gonopod.

Key words: Freshwater crab, Gecarcinucoidea, New species, New genus, Malaysia, Brunei, Indonesia, Taxonomy, Distribution, Key.

Citation: Ng PKL, Grinang J. 2022. Establishment of a new Bornean genus of Gecarcinucidae (Crustacea: Brachyura), with descriptions of five new species. Zool Stud 61:13. doi:10.6620/ZS.2022.61-13.