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| Ghatiana dvivarna Pati, Thackeray, Bajantri & Hegde, 2022 |
Abstract
A new species of the freshwater crab genus Ghatiana Pati and Sharma, 2014, is recognized herein from the Karnataka State, India. Ghatiana dvivarna sp. nov. usually inhabits holes in the laterite rocks on the elevated mountains of the Central Western Ghats (south of Goa-Nilgiris). The predominantly white color in life and the characteristic smaller eyes relative to the orbits of the new species easily distinguish it from congeners. Ghatiana dvivarna sp. nov. most resembles Ghatiana pulchra Pati and Thackeray, 2018, but can be differentiated mainly by its relatively more slender terminal segment of the male first gonopod. Ghatiana currently comprises 11 species, now including Ghatiana dvivarna sp. nov.
Keywords: Crustacea; Decapoda; Gecarcinucoidea; Karnataka; Oriental region; taxonomy
Superfamily Gecarcinucoidea Rathbun, 1904
Family Gecarcinucidae Rathbun, 1904
Ghatiana Pati and Sharma, 2014
Type species. Ghatiana aurantiaca Pati and Sharma, 2014, by original designation; gender feminine.
Remarks. The genus is characterized by the combination of the following morphological characters: the frontal margin is relatively narrow; the first and second maxillipeds each possesses a distinct flagellum on the exopod; the flagellum on the relatively longer exopod of the third maxilliped is absent; the male pleon is relatively stouter, with a relatively squarish pleonite somite 6; the male telson is elongated; G1 is relatively stouter and shorter; G2 is very short, with a very short distal segment (Pati and Thackeray, 2018; 2021).
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| Ghatiana dvivarna sp. nov., color in life. A, Holotype male (24.66 × 13.61 mm) (ZSI-WRC C.2075); B, paratype female (29.97 × 15.98 mm) (ZSI-WRC C.2076). |
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| Ghatiana dvivarna sp. nov., holotype male (24.66 × 13.61 mm) (ZSI-WRC C.2075). A, Overall dorsal view; B, overall frontal view; C, overall ventral view. Scale bar = 10 mm. |
Ghatiana dvivarna sp. nov.
Type locality. India, Karnataka State, Uttara Kannada District, Bare, 1..., alt. 656 m.
Diagnosis. Carapace in adult proportionately broad (CW/CL = 1.7-1.9), strongly arched (CH/CL = 0.7) (Figs. 3A, B, 5A, B, 7B); lateral margins strongly convex (Figs. 3A, 5A, 7B); anterolateral margins relatively short, cristate (Figs. 3A, 5A, 7B); epibranchial tooth visible as weak notch (Figs. 3A, 5A); branchial regions rugose (Figs. 3A, 5A); frontal margin relatively close to anterior margin of epistome, hiding antennular fossae (Figs. 3B, 5B, 7A). Eyes small relative to orbits; each eye with relatively slender eyestalk (Figs. 3B, 5B, 7A). First, second maxillipeds each with short flagellum on exopod; third maxilliped lacking flagellum on exopod (Fig. 4A). Chelipeds in both males and females highly unequal, with pointed fingertips (Figs. 3A-C, 5A, B, 7E); major chela with relatively slender palm (Figs. 4B, 7E); ventral margin of fixed finger and distal half of palm of major chela gently concave (Figs. 4B, 7E). Ambulatory legs relatively short (P3 length/CL = approximately 2.0) (Figs. 3A, 5A). Male pleonal somite 6 subquadrate, slightly broader than long (Figs. 3C, 4C). Male telson elongated (Figs. 3C, 4C). G1 relatively slender, almost straight; terminal segment relatively slender, straight, relatively long, approximately 0.5 times length of subterminal segment; subterminal segment relatively slender (Figs. 4D, E, 7C). G2 very short, with very short distal segment (Fig. 4F). Female pleon and telson in adult broadly subtriangular (Fig. 5C). Vulvae in adult relatively closely positioned (VD/SW = approximately 0.2), each subovate in shape, relatively large, occupying approximately 0.5 times length of s6, positioned close to s5/s6 (Figs. 5D, 7D).
Etymology. The specific epithet, dvivarna, is derived from the Sanskrit for ‘bicolor’, referring to the crab's colour in life, which mainly consists of two colours (white and red-violet). The name is conceived here as a noun in apposition.
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| Ghatiana dvivarna sp. nov. A, View of the general habitat at the type locality; B, a crab in its natural habitat; C, a crab while feeding on the mosses growing on a laterite rock. |
Ecological notes. The species inhabits elevated mountains of the Central Western Ghats in rocky outcrops with grassy vegetation (Fig. 6A). The holes (25-50 mm in diameter) in the laterite rocks are their natural habitat (Fig. 6B) (see youtu.be/d4lf_DoOwtQ). Individuals can also take shelter underneath small boulders. These crabs are generally seen during the monsoon (June-September). They are mostly active during the twilight. As many as 30-40 crabs/500 m2 can be seen during this time when the weather is very cloudy with precipitation or mist. Their activities minimize when rain halts, and the crabs during this time can be found in the rocky holes filled with rainwater. Some crabs were seen eating mosses growing on laterite rocks (Fig. 6C). Females carrying juvenile crabs were observed in the rocky holes.
Sameer Kumar Pati, Tejas Thackeray, Parashuram Prabhu Bajantri and Gopalkrishna Dattatraya Hegde. 2022. A New Species of the Freshwater Crab Genus Ghatiana Pati and Sharma, 2014 (Brachyura: Gecarcinucidae) from the Central Western Ghats, India. Nauplius. 30 • DOI: 10.1590/2358-2936e2022019
