Silhouettea indica (Visweswara Rao, 1971)

Common name - Indian silhouette goby

Material examined: ZSI/SbRC/KN 3089, 1 ex, (TL

31.8 mm, SL 24.3 mm, BD 4.5 mm, HL 10.1 mm), Pullivasal Island, Gulf of Mannar Marine National Park (9°14’55.01”N; 79°11’3.25”E), 24.01.2020, Coll: Sreeraj, C. R .

Diagnostic characters: Silhouettea indica is diagnosed from congeners in having a combination of the following characters - First dorsal VI; Second dorsal I, 10; Anal I, 12; Pectoral rays 15; Caudal fin rays 15. Small fish with elongated and compressed body. Depressed head with dorso-laterally situated eyes. Terminal and oblique mouth with prominent lower jaw. 2-3 medially placed caniniform teeth on jaws. Gill opening extending below the rear margin of preopercle. Caudal peduncle compressed and rounded caudal fin. Ctenoid scales. No scales on cheek or opercle. Light muddy coloured body with pale white ventral region, small dark brown blotches scattered above the mid dorsal as well as head region. Pale white coloured dorsal fins yellow coloured dorsally with white fin tip. Lateral rows of orange/red blotches on the dorsal fins. Caudal fin with orange and white vertical stripes and narrow white coloured fin outline, Anal fin dark brown in colour (Figure 3).

Distribution: India: Godavari estuary, Andhra Pradesh (Padmavathi, 2017), GoM (Present study). Elsewhere: Endemic to India.

Remarks: Found solitary in the shallow (less than 30 cm depth) silty coral reef area. The bend head and gape in the specimen happened due to death by asphyxiation (Figure 3). As the breakwater zone is rich in oxygen saturation, this species cannot survive in low oxygenated normal water. It is quite tough to point out the specimen in this zone and so far, no work on this genus had been done after Rao discovered it on 1971.