Thalamita gatavakensis Nobili 1906
Creators: name: Padate, Vinay P.
name: Periasamy, Rengaiyan
name: Rivonker, Chandrashekher U.
name: Ingole, Baban S.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Portunidae
Thalamita
Thalamita gatavakensis

description: Thalamita gatavakensis Nobili, 1906
(Fig. 4E–H)
Thalamita pilumnoides var. gatavakensis Nobili, 1906b: 262, figs. 30a–b, 31a–e (type locality: Gatavaké, French Polynesia).
Thalamita pilumnoides ssp. gatavakensis.— Forest & Guinot 1961: 34, figs. 22a–b, 23–25.
Thalamita gatavakensis.— Crosnier 1962: 106, figs. 177a–d.— Stephenson & Rees 1967: 75.— Stephenson 1972a: 149.— Stephenson 1972b: 20 (key), 47.— Wee & Ng 1995: 82, figs. 43a–d.— Stephenson 1976: 21.
Thalamita granosimana.— Stephenson 1961: 119, figs. 2E, 4A, pl. 3, fig. 4, pls. 4J, 5G. [Not T. granosimana Borradaile, 1903)]
Material examined. 2 males (5.1 × 3.1 mm, 5.7 × 3.4 mm) (NIO /BOD/AB/BRY/00011), RVSS 11, west of Vijaydurg, Arabian Sea, 16.62°N, 72.01°E, 24 m depth, Van Veen grab, coll. R. Periasamy, 8 January 2014.
Diagnosis. Carapace hexagonal, tomentose (Fig. 4E); frontal margin bilobed, internal orbital angles narrower than frontal lobes; carapace ridges including 1 pair each of frontals, protogastrics, mesogastrics, mesobranchials and epibranchials, median metagastric and cardiac ridges; anterolateral margins divided into 5 teeth, fourth tooth rudimentary (Fig. 4F). Basal antennal article with 8 tubercles (Fig. 4G). Cheliped merus with 3 spines on anterior margin; manus with 6 spines on dorsal surface (Fig. 4E). G1 distal tip recurved spoon-shaped, with spine on spoonedtip, inner surface with long backwardly directed spine and inner surface with 3–4 bristles (Fig. 4H).
Colouration. Fresh specimen: carapace reddish brown with yellowish speckles (Fig. 4E). Preserved specimen: brown with lighter setae (Fig. 4F).
Biology. Known to inhabit corals (Wee & Ng 1995) in intertidal coralline sand (Crosnier 1962) and lagoons (Forest & Guinot 1961); 20–24 m (Wee & Ng 1995; present study). The present specimens were collected from sandy substratum, at 24 m depth, covered with macroalgae.
Remarks. Nobili (1906b) provided a short description of a new variety (gatavakensis) of T. pilumnoides from French Polynesia. Forest & Guinot (1961) compared T. pilumnoides gatavakensis with T. pilumnoides and proposed its elevation to species level. Crosnier (1962) provided a short, illustrated description of T. gatavakensis and elevated it to species level based on the differences (with T. pilumnoides) in morphologies of male pleon and G1. Stephenson’s (1972b) key to the Indo-West Pacific portunids grouped this species along with T. iranica Stephensen, 1946, T. granosimana Borradaile, 1902, T. admete (Herbst, 1803), T. auauensis Rathbun, 1906 and T. gloriensis Crosnier, 1962 owing to G1 with moderately curved tip. This species differs from the above-mentioned congeners in having G1 with curved distal tip bearing very few setae. Wee & Ng (1995) provided a short, illustrated description of T. gatavakensis. The morphology of the present specimens conformed to the descriptions and illustrations provided by Crosnier (1962) and Wee & Ng (1995) in the bilobed frontal margin of carapace, the presence of cardiac ridge and mesobranchial ridges in addition to 1 pair each of frontal, protogastric, mesogastric, metagastric and epibranchial ridges, a straight inner supraorbital lobe narrower than the frontal lobe, and a spoon-shaped, recurved distal tip of G1 bearing very few terminal bristles.
Geographical distribution. Madagascar, Seychelles, Malaysia, Philippines, Indonesia, Western Australia, Saipan, Tuamotu (Wee & Ng 1995); eastern Arabian Sea off India (present study). The present observation is the first record from Indian waters.
description: Published as part of Padate, Vinay P., Periasamy, Rengaiyan, Rivonker, Chandrashekher U. & Ingole, Baban S., 2023, Coral reef-associated brachyuran fauna (Crustacea: Decapoda: Brachyura) from Angria Bank off the west coast of India, pp. 398-422 in Zootaxa 5357 (3) on pages 407-408, DOI: 10.11646/zootaxa.5357.3.4, http://zenodo.org/record/10063288