Ghatiana durrelli n. sp.

(Figs 1 A-D; 2 A-H; 3 A, B)

urn:lsid:zoobank.org:act: ED5952DC-3544-434B-ADD6-CEC5BE37DF67

TYPE MATERIAL. — Holotype. India • ♂ (CW 19.53 mm, CL 13.19 mm, CH 9.38 mm, FW 7.19 mm); Maharashtra: Satara district: Ramban Trail, Koyna Wildlife Sanctuary; 17°25’58”N, 73°42’32”E; alt. 940 m; 1.VII.2017; Tejas Thackeray leg.; ZSI-WRC C.1999.

Paratypes. India • 3 ♂ (CW 14.18-17.84 mm, CL 9.17-12.22 mm, CH 6.01-7.86 mm, FW 5.42-6.83 mm); 3 ♀ (CW 16.06-22.83 mm, CL 10.66-15.04 mm, CH 7.46-10.64 mm, FW 6.06-8.40 mm); same data as for holotype; ZSI-WRC C.2000 .

OTHER MATERIAL. — India • ♂ (CW 13.77 mm, CL 9.45 mm, CH 5.96 mm, FW 5.08 mm), 2 ♀ (CW 18.91-21.89 mm, CL 12.64- 14.51 mm, CH 8.66-9.78 mm, FW 6.82-7.46 mm); Maharashtra: Kolhapur district: Kokan Darshan Point, Masnoli village, c. 5 km south of Amba; 16°55’22”N, 73°47’45”E; alt. 840 m; 15.VII.2020; Tejas Thackeray leg.; ZSI-WRC C.2001 .

TYPE LOCALITY. — India: Maharashtra: Satara district: RambanTrail, Koyna Wildlife Sanctuary; 17°25’58.8”N, 73°42’32.4”E; alt. 940 m.

DIAGNOSIS. — Carapace in adult proportionately narrow (CW/ CL = 1.5), moderately to strongly arched (CH /CL = 0.6-0.7); lateral margins strongly convex; anterolateral margins relatively short, cristate; epibranchial tooth visible as weak notch; branchial regions slightly rugose; frontal margin some distance from anterior margin of epistome, exposing antennular fossae (Fig. 1 A-C). First, second maxillipeds with long flagellum on exopod; third maxilliped lacking flagellum on exopod (Fig. 2A). Major chela with pointed fingertips; palm in adult male relatively stout; ventral margin of fixed finger and distal half of palm in adult male strongly concave (Figs 1A, D; 2B). Ambulatory legs relatively long (P3 length/CL = c. 2.3) (Fig. 1A). Male pleonal somite 6 subquadrate, slightly broader than long (Figs 1D; 2C). Male telson elongated (Figs 1D; 2C). G1 relatively slender, almost straight; terminal segment relatively stout, distally gently curved inwards, relatively long, c. 0.5 times length of subterminal segment; subterminal segment relatively slender (Fig. 2D, E). G2 very short, with very short distal segment (Fig. 2F). Female pleon in adult broadly subtriangular (Fig. 2G). Vulvae in adult positioned apart from each other (VD/SW = c. 0.3), each subovate in shape, relatively large, occupying c. 0.4 times length of S6, positioned close to S5/S6 (Fig. 2H).

ETYMOLOGY. — The species name honours British naturalist, Gerald Malcolm Durrell for his in situ and ex situ conservation efforts. The specific epithet is thus conceived as a noun in the genitive singular.

COLOUR IN LIFE. — The crabs show colour variations. They are generally fluorescent red dorsally (Fig. 3A) and relatively paler ventrally. Some crabs are reddish brown dorsally (Fig. 3B).

ECOLOGICAL NOTES. — Ghatiana durrelli n. sp. is a nocturnal crab and is found in tree trunk holes and in holes or crevices of laterite rocks (locally known as “Jambha”). The species occurs at elevated mountains (840-940 m altitude). Some individuals were observed feeding on dead millipedes.

GEOGRAPHICAL DISTRIBUTION. — Ghatiana durrelli n. sp. is currently known only from two localities of Maharashtra state (Kolhapur and Satara districts), India. Both the localities are situated in the Western Ghats.

REMARKS

Ghatiana durrelli n. sp. most closely resembles to G. aurantiaca (type species) mainly due to the proportionately narrower adult carapace [CW/CL = 1.5 in G. durrelli n. sp. (Fig. 1A, B); CW/CL = 1.4 in G. aurantiaca (see Pati & Sharma 2014: fig. 2A; Pati & Thackeray 2018: fig. 4A)], the exposed fossae due to the gap between the frontal margin and the anterior margin of the epistome (Fig. 1C; see Pati & Sharma 2014: fig. 2B; Pati & Thackeray 2018: fig. 4B), and an almost straight G1 (Fig. 2D, E; see Pati & Sharma 2014: fig. 3E, F; Pati & Thackeray 2018: fig. 4D, E). Ghatiana durrelli n. sp., however, is differentiated from G. aurantiaca by the relatively broader male pleonal somite 6 (Figs 1D; 2C) (vs male pleonal somite 6 as long as broad; see Pati & Sharma 2014: figs 2C, 3B; Pati & Thackeray 2018: fig. 4C), the relatively stouter G1 terminal segment (Fig. 2D, E) (vs G1 terminal segment relatively slenderer; see Pati & Sharma 2014: fig. 3E-G; Pati & Thackeray 2018: fig. 4D, E), the relatively slenderer G1 subterminal segment (Fig. 2D, E) (vs G1 subterminal segment relatively stouter; see Pati & Sharma 2014: fig. 3E, F; Pati & Thackeray 2018: fig. 4D, E), and the relatively closely positioned adult vulva in relation to S5/S6 (Fig. 2H) (vs adult vulva positioned a clear distance from S5/S6; see Pati & Thackeray 2018: fig. 4H).

Among congeners, the stout G1 terminal segment is unique in G. durrelli n. sp. and G. pulchra Pati & Thackeray, 2018 (Fig. 2D; see Pati & Thackeray 2018: fig. 8I, J). In fact, the G1 structure of G. durrelli n. sp. is almost identical to that of G. pulchra except for the gently inwardly curved terminal segment (Fig. 2D) (vs straight G1 terminal segment in G. pulchra; see Pati & Thackeray 2018: fig. 8I, J). Ghatiana durrelli n. sp. can nevertheless be separated from G. pulchra by the proportionately narrower adult carapace, CW/CL = 1.5 (Fig. 1A, B) (vs proportionately broader adult carapace, CW/CL = 1.6; see Pati & Thackeray 2018: fig. 8A), the strongly concave ventral margin of the fixed finger and the distal half of the palm of the major chela in adult males (Fig. 2B) (vs gently concave ventral margin of the fixed finger and the distal half of the palm of the major chela in adult males; see Pati & Thackeray 2018: fig. 8D), and the relatively longer ambulatory legs, P3 length/CL = c. 2.3 (Fig. 1A) (vs the relatively shorter ambulatory legs, P3 length/CL = c. 2.0; see Pati & Thackeray 2018: fig. 8A).