Borneosa Ng & Grinang 2022
Creators: name: Ng, Peter K L
name: Grinang, Jongkar
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Gecarcinucidae
Borneosa

description: Key to species of Borneosa
1a. Anterolateral margin with the epibranchial tooth distinct, sharp, separated from rest of anterolateral margin by clear cleft (e.g., Figs. 10B, 11F, H); male sternoplenonal cavity separated from suture between thoracic sternites 2 and 3 by narrow gap, less than combined length of thoracic sternites 1 and 2 (e.g., Fig. 18B) .. 2
1b. Anterolateral margin with the epibranchial tooth low to almost absent, cleft when visible, low, shallow, anterolateral margin may appear entire (e.g., Fig. 2B); male sternoplenonal cavity separated from suture between thoracic sternites 2 and 3 by relatively wide gap, more than combined length of thoracic sternites 1 and 2 (e.g., Fig. 3B) ....................................................................................... 4
© 2022 Academia Sinica, Taiwan
2a. Outer margin of exorbital tooth distinctly serrated (Fig. 17B); Bulungan, Kalimantan Utara ........................... B. serrata sp. nov.
2b. Outer margin of exorbital tooth entire or almost so (e.g., Fig. 8B); Sarawak ...................................................................................... 3
3a. Epibranchial tooth low, separated from anterolateral margin by small cleft (Fig. 8B); third maxilliped ischium subquadrate (Fig. 9A); G1 terminal segment relatively slender, long (Fig. 21A–C); Niah, Sarawak ..................................................... B. niah sp. nov.
3b. Epibranchial tooth strong, separated from anterolateral margin by prominent U-shaped cleft (Figs. 10B, 11F, H); third maxilliped ischium subrectangular (Fig. 11A); G1 terminal segment relatively stout, short (Fig. 21E–G); Bario Highlands, Sarawak .. ............................................................................. B. bario sp. nov.
4a. P3 dactylus distinctly more slender and elongate compared to P4 dactylus (e.g., Fig. 5H, I) ............................................................ 5
4b. P3 and P4 dactyli not elongate, subequal in length (e.g., Fig. 7F, G) ................................................................................................ 6
5a. Frontal median triangle with dorsal margin separated from lateral margins by small gap (Fig. 2C–F); G1 terminal segment relatively short, subcylindrical (Fig. 20F, G, J, K); Gunong Mulu National Park, Sarawak ................. B. tenebrosa (Holthuis, 1979)
5b. Frontal median triangle with dorsal margin contiguous with lateral margins (Fig. 4C–E); G1 terminal segment very long, cylindrical (Fig. 20M–O); Brunei and northern Sabah ................. .................................................. B. aspera (Ng & Stuebing, 1989)
6a. Striae on lateral parts of dorsal surface of carapace relatively lower, rounded (Figs. 6B, 7I); median lobe of posterior margin of epistome acutely triangular (Fig. 6C–E) ....................................... ............. Barito, Kalimantan Tengah B. brachyphallus (Ng, 2015)
6b. Striae on lateral parts of dorsal surface of carapace strong, sharp (Fig. 15B); median lobe of posterior margin of epistome obtusely triangular (e.g., Fig. 15C–E) ...................................................... 7
7a. Epibranchial tooth small but usually visible, and even when low, demarcated from the anterolateral margin by a shallow cleft (Figs. 12B, 14); G1 terminal segment with median part less distinctly bent, distal part more elongate with more tapering tip, opening small (Fig. 22A–C, E–G); Kapit area and upper Rejang, Sarawak ............................................................................. B. kapit sp. nov.
7b. Epibranchial tooth not visible or very low, with the anterolateral margin appearing entire (Fig. 15B); G1 terminal segment with median part distinctly bent, distal part ending in rounded tip with wide opening (Fig. 22I–K); Batang Ai National Park and Lanjak-Entimau Wildlife Sanctuary, Kanowit Basin, Sarawak ................. ................................................................ B. sarawakensis sp. nov.
description: Published as part of Ng, Peter K L & Grinang, Jongkar, 2022, Establishment of A New Bornean Genus of Gecarcinucidae (Crustacea: Brachyura), with Descriptions of Five New Species., pp. 1-35 in Zoological Studies 61 (13) on pages 32-33, DOI: 10.6620/ZS.2022.61-13, http://zenodo.org/record/8074520