Ghatiana sanguinolenta, Pati & Thackeray & Pawar, 2023

Pati, Sameer Kumar, Thackeray, Tejas & Pawar, Swapnil, 2023, Ghatiana sanguinolenta, a new species of freshwater crab (Brachyura: Gecarcinucidae) from the Central Western Ghats of India, Zootaxa 5353 (4), pp. 372-378 : 374-377

publication ID	https://doi.org/ 10.11646/zootaxa.5353.4.4
publication LSID	lsid:zoobank.org:pub:DBCD0660-BFF4-4507-8BC7-F6339450B011
DOI	https://doi.org/10.5281/zenodo.8431445
persistent identifier	https://treatment.plazi.org/id/252E6C9C-4447-4308-B123-CB1EDE8B865D
taxon LSID	lsid:zoobank.org:act:252E6C9C-4447-4308-B123-CB1EDE8B865D
treatment provided by	Plazi
scientific name	Ghatiana sanguinolenta
status	sp. nov.

Treatment

Ghatiana sanguinolenta sp. nov.

[Blood-red Ghat Crab]

( Figs. 2 View FIGURE 2 , 3 View FIGURE 3 , 4 View FIGURE 4 )

Type material. HOLOTYPE: ZSI-WRC C.2353 , adult male (CW 24.48 mm, CL 15.38 mm, CH 10.28 mm, FW 9.04 mm), Balekoppa , near Devimane on Sirsi-Kumta road, Uttara Kannada district, Karnataka state, India, 14.527°N, 74.596°E, altitude 413 m a.s.l., coll. Swapnil Pawar, 1 September 2021. GoogleMaps

PARATYPES: ZSI-WRC C.2354 , adult male (CW 28.53 mm, CL 17.85 mm, CH 12.82 mm, FW 10.40 mm), 2 adult females (CW 26.39–28.45 mm, CL 16.84–18.26 mm, CH 12.38–12.71 mm, FW 9.79–10.39 mm), same collection data as for holotype GoogleMaps .

Diagnosis. Carapace in adult proportionately broad (CW/CL = 1.6) ( Figs. 2A View FIGURE 2 , 3A, C View FIGURE 3 ), strongly arched ( CH / CL = 0.7) ( Fig. 2B View FIGURE 2 ); lateral margins strongly convex ( Figs. 2A View FIGURE 2 , 3A, C View FIGURE 3 ); anterolateral margins relatively short, subcristate ( Figs. 2A View FIGURE 2 , 3A, C View FIGURE 3 ); epibranchial tooth visible as weak notch ( Figs. 2A View FIGURE 2 , 3A, C View FIGURE 3 ); branchial regions rugose ( Figs. 2A View FIGURE 2 , 3A, C View FIGURE 3 ); frontal margin relatively close to anterior margin of epistome, almost hiding antennular fossae ( Fig. 2B View FIGURE 2 ). Eyes relatively small as compared to orbital space; each eye with relatively slenderer eyestalk ( Fig. 2B View FIGURE 2 ). Maxilliped 1, 2 each with short flagellum on exopod ( Fig. 2D View FIGURE 2 ); maxilliped 3 exopod without flagellum ( Fig. 2E View FIGURE 2 ). Major chela in adult male with pointed fingertips; palm in adult male relatively stout; ventral margin of fixed finger and distal half of palm in adult male strongly concave ( Fig. 2F View FIGURE 2 ). Ambulatory legs relatively long (P3 length/CL = ca. 2.5) ( Figs. 2A, C View FIGURE 2 , 3A, C View FIGURE 3 ). Male pleonal somite 6 subquadrate ( Figs. 2C, G View FIGURE 2 , 3B View FIGURE 3 ). Male telson elongated ( Figs. 2C, G View FIGURE 2 , 3B View FIGURE 3 ). G1 relatively slender, medially gently curved outwards; ultimate article relatively slender, distally gently curved outwards, relatively long, ca. 0.4 times length of penultimate article; penultimate article relatively slender ( Fig. 2H, I View FIGURE 2 ). G2 very short, with very short penultimate article ( Fig. 2J View FIGURE 2 ). Female pleon and telson in adult broadly subtriangular, with lateral margins of telson strongly concave ( Fig. 3D View FIGURE 3 ). Vulvae in adult relatively closely positioned (VD/SW = ca. 0.25), each subovate in shape, relatively large, occupying ca. 0.5 times length of s6, positioned close to s5/s6 ( Fig. 3E View FIGURE 3 ).

Colour in life. Crabs have dark blood-red coloured carapace and pereiopods, with blanched fingers ( Fig. 4 View FIGURE 4 ).

Etymology. The specific epithet, ‘sanguinolenta’ meaning blood-red, is a Latin adjective in the nominative singular, which alludes to the crab's colour in life.

The proposed common name of the new species is “Blood-red Ghat Crab”.

Ecological notes. Ghatiana sanguinolenta sp. nov. dwells in the forests of the Central Western Ghats. These crabs live in tree holes during the evening and night-time. Juveniles were found living with adults in some tree holes. Individuals can also forage on open ground in non-forested areas.

Remarks. In diagnostic features, the paratype male (ZSI-WRC C.2354) of G. sanguinolenta sp. nov. is indistinguishable from the holotype. The male paratype differs from the holotype only by the shape of the pleonal somite 6, which is slightly longer than broad ( Fig. 3B View FIGURE 3 ) (vs. slightly broader than long in the holotype; Fig. 2G View FIGURE 2 ). The female paratypes (ZSI-WRC C.2354) are consistent with the holotype in non-sexual diagnostic characters.

The dark blood-red colour-in-life of Ghatiana sanguinolenta sp. nov. is unique in the genus, which is convenient for identifying the species in field. The outwardly curved ultimate article of the G1 is characteristic of G. sanguinolenta sp. nov. ( Fig. 2H View FIGURE 2 ), whereas the remaining species of Ghatiana possess a straight or inwardly curved G1 ultimate article (see Pati & Thackeray 2018: figs. 3D, 4D, 5D, 6I, 7D, 8I, 9I, 10D; Pati & Thackeray 2021: figs. 2D, 5D; Pati et al. 2022a: fig. 4D). The new species otherwise most closely resembles G. basalticola , G. dvivarna , and G. pulchra Pati & Thackeray, 2018 , in having a proportionately broader carapace (CW/CL = 1.6–1.9) ( Fig. 2A View FIGURE 2 ; see Pati & Thackeray 2018: figs. 5A, 8A; Pati et al. 2022a: fig. 3A).

Ghatiana sanguinolenta sp. nov., G. dvivarna and G. pulchra can be distinguished from G. basalticola by the G1, which is almost straight or medially gently curved outwards, with the ultimate article being relatively longer, ca. 0.4–0.5 times the length of the penultimate article ( Fig. 2H View FIGURE 2 ; see Pati & Thackeray 2018: fig. 8I; Pati et al. 2022a: fig. 4D) (vs. G1 medially distinctly curved outwards, with the ultimate article being relatively shorter, ca. 0.3 times the length of the penultimate article in G. basalticola ; see Pati & Thackeray 2018: fig. 5D).

Ghatiana sanguinolenta sp. nov. and G. dvivarna are immediately differentiated from G. pulchra by the form of the frontal margin, which is relatively close to the anterior margin of the epistome and conceals the antennular fossae ( Fig. 2B View FIGURE 2 ; see Pati et al. 2022a: fig. 3B) (vs. frontal margin some distance from the anterior margin of the epistome exposing the antennular fossae in G. pulchra ; see Pati & Thackeray 2018: fig. 8B); the eye being relatively small as compared to the orbital space, with the relatively slender eyestalk ( Fig. 2B View FIGURE 2 ; see Pati et al. 2022a: fig. 3B) (vs. eye relatively large as compared to the orbital space, with the relatively stout eyestalk in G. pulchra ; see Pati & Thackeray 2018: fig. 8B); and the G1 ultimate article being comparatively more slender ( Fig. 2H View FIGURE 2 ; see Pati et al. 2022a: fig. 4D) than in G. pulchra (see Pati & Thackeray 2018: fig. 8I).

The morphological resemblance of the new species to G. dvivarna notwithstanding, G. sanguinolenta sp. nov. is separated from G. dvivarna in having a relatively stout palm of the major chela of the adult males, with the strongly concave ventral margin of the fixed finger and the distal half of the palm ( Fig. 2F View FIGURE 2 ) (vs. major chela with relatively slender palm in adult males, with gently concave ventral margin of the fixed finger and the distal half of the palm; see Pati et al. 2022a: fig. 4B); the outwardly curved and relatively shorter ultimate article of the G1, ca. 0.4 times the length of the penultimate article ( Fig. 2H View FIGURE 2 ) (vs. G1 ultimate article straight and relatively longer, ca. 0.5 times the length of the penultimate article; see Pati et al. 2022a: fig. 4D); and the strongly concave lateral margins of the female telson ( Fig. 3D View FIGURE 3 ) (vs. female telson with almost straight lateral margins; see Pati et al. 2022a: fig. 5C). Both G. sanguinolenta sp. nov. and G. dvivarna are known only from the Western Ghats of Uttara Kannada district in Karnataka ( Pati et al. 2022a; present study). Although the type locality of G. sanguinolenta sp. nov. is some 30 km away from the type locality of G. dvivarna , their respective type localities are situated in the isolated mountains separated by the Gangavali River and the deep valley, which could represent the geographic barriers in the form of “sky islands” (see Pati et al. 2023b).

Ghatiana atropurpurea and G. rouxi are likely to be encountered along with the new species. Ghatiana sanguinolenta sp. nov. is easily differentiated from them mainly by the proportionately broader carapace, CW/CL = 1.6 ( Fig. 2A View FIGURE 2 ) (vs. carapace proportionately narrower, CW/CL = 1.2–1.5 in G. atropurpurea and G. rouxi ; see Pati & Thackeray 2018: fig. 3A; 2021: 4A); the relatively small eye as compared to the orbital space, with the eyestalk relatively slender ( Fig. 2B View FIGURE 2 ) (vs. eye relatively large as compared to the orbital space, with the eyestalk relatively stout in G. atropurpurea and G. rouxi ; see Pati & Thackeray 2018: fig. 3B; 2021: 4C); and the outwardly curved and relatively shorter ultimate article of the G1, which is about 0.4 times the length of the penultimate article ( Fig. 2H View FIGURE 2 ) (vs. G1 ultimate article inwardly curved and relatively longer, ca. 0.5 times the length of the penultimate article in G. atropurpurea and G. rouxi ; see Pati & Thackeray 2018: fig. 3D; 2021: 5D).

Geographical distribution. Ghatiana sanguinolenta sp. nov. is currently known only from the type locality, i.e., Balekoppa in Uttara Kannada district of Karnataka state. The type locality is situated in the Central Western Ghats of India ( Fig. 1 View FIGURE 1 ).