Capitamon mizoramense Pati, Mitra & Ng, 2024, n. sp.
Creators: name: Pati, Sameer K.
name: Mitra, Santanu
name: Ng, Peter K. L.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Potamidae
Capitamon
Capitamon mizoramense

description: Capitamon mizoramense n. sp.
(Figs 15; 16; 17)
urn:lsid:zoobank.org:act: 325C0E17-991F-43A7-9D11-48CD57D41299
Indochinamon beieri – Mitra 2017: 23, figs 49-51; 71; 113-115 [not Potamon beieri Pretzmann, 1966].
TYPE MATERIAL. — Holotype. India • ♂ (46.3 × 35.7 mm); Mizoram state: Champhai district: Zokhawthar, c. 2 km from Indo-Myanmar International Border, collected from small stream connected to Tiau River; 23°21’53”N, 93°23’9”E; alt. 728 m; 23.IX.2013; S. Mitra leg.; ZSIK C.6122/2A.
Paratypes. India • ♂ (31.4 × 24.9 mm), ♀ (51.3 × 37.6 mm); same data as for holotype; ZSIK C.6122/2B • 7 ♂ (largest male, 60.0 × 44.6 mm), 4 ♀ (largest female, 52.0 × 39.6 mm); Mizoram state: Lunglei district: Tui-pui village, collected from small stream connected to Tui-pui River; 22°52’47”N, 92°56’9”E; alt. 228 m; 24.IX.2013; S. Mitra leg.; ZSIK C.6131/2 • 5 ♂ (largest male, 37.5 × 29.2 mm), 4 ♀ (largest female, 37.7 × 28.8 mm); Mizoram state: Serchhip district: near Vantawng waterfalls, about 9 km from Thenzawl market, collected from small water channel; 23°14’2”N, 92°45’3”E; alt. 720 m; 26.IX.2013; S. Mitra leg.; ZSIK C.6125/2.
DIAGNOSIS. — Carapace ovate, broader than long (CW/CL = 1.3), relatively low (CH /CW = 0.4); epigastric cristae well-developed, rugose; postorbital cristae well-developed, relatively sharp, oblique in dorsal view; external orbital angle triangular, with short outer margin, c. 2 × inner margin; epibranchial tooth low, blunt, positioned above level of postorbital cristae; cervical grooves discontinuous, not reaching to level of postorbital cristae; epistome posterior margin with well-developed, triangular median tooth, outer parts sloping downwards (Fig. 15A, B). Third maxilliped exopod with short flagellum, shorter than width of merus (Fig. 16B). Chelipeds rugose, unequal, inner distal tooth on carpus relatively narrow (Figs 15A, C; 16C). Male s3/ s4 indiscernible except for two short lateral clefts (Figs 15C; 16D). Male pleonal somite 6 relatively broader (proximal width c. 2.1 × medial length), equal in length to pleonal somite 5, with gently convex lateral margins (Figs 15C; 16E). Male telson relatively broader (proximal width c. 1.3 × medial length), with concave lateral margins (Figs 15C; 16E). G1 ultimate article relatively more strongly bent at angle of about 110° from longitudinal axis, with sinuous outer margin, dorsal flap relatively high, narrowly triangular (Figs 16F; 17A, C-E). G2 c. 1.3 × length of G1; ultimate article long, c. 0.6 × length of penultimate article (Figs 16F, G; 17B, D). Vulvae laterally partially covered by protruding sternal cover, visible in ventral view (Fig. 16I).
ETYMOLOGY. — The specific epithet refers to Mizoram state in northeastern India, where the new species is found.
COLOUR IN LIFE. — Crabs are olive green or brown, with paler ventral side and blood red joints of chelipeds (see Mitra 2017: fig. 71).
ECOLOGICAL NOTES (modified from Mitra 2017). — Capitamon mizoramense n. gen., n. sp. is a hill stream crab that prefers rocky habitats. This species is very common in the Champhai district of Mizoram. Local fishermen catch these crabs at night and sell them alive in the early morning for food. The population of this species may decline in the near future if these crabs are over-harvested.
GEOGRAPHICAL DISTRIBUTION. — Capitamon mizoramense n. gen., n. sp. is known only from Mizoram state of northeastern India (Fig. 1).
REMARKS
Capitamon mizoramense n. gen., n. sp. is unique among congeners due to the G1 ultimate article, which is relatively more strongly bent at an angle of about 110° from longitudinal axis of the G1, and possesses the relatively high and narrowly triangular dorsal flap (Figs 16F; 17A, C-E). The remaining nominal species of Capitamon n. gen. have a G1 ultimate article relatively less strongly bent at an angle of about 60-75° from longitudinal axis of the G1 (Figs 6F; 7D, E; 8C; 10A; 11D, E; 13F; 14D, E; see Pati et al. 2020: figs 4a, d; 5a, c). Capitamon mizoramense n. gen., n. sp. shares the following features of the G1 with C. meitei n. gen., n. sp.: sinuous outer margin of the G1 ultimate article and the relatively high, narrowly triangular dorsal flap on the G1 ultimate article (Figs 13F; 14A, C-E; 16F; 17A, C-E). Other features of G1 and vulvae, however, distinguish them (see Remarks for C. meitei n. gen., n. sp.).
description: Published as part of Pati, Sameer K., Mitra, Santanu & Ng, Peter K. L., 2024, Identity of the freshwater crab Indochinamon beieri (Pretzmann, 1966), with the description of a new genus and four new species from northeastern India (Decapoda, Brachyura, Potamidae), pp. 589-615 in Zoosystema 46 (23) on pages 609-612, DOI: 10.5252/zoosystema2024v46a23, http://zenodo.org/record/13837101