Decorated Sandgoby

Istigobius decoratus is a species of gobies found in fresh, brackish and marine waters of the regions along the coasts of the Indian and western Pacific oceans.

Description

Color is highly variable, brownish on upper half, grading to white below. It has dark brown scale margins forming honeycomb pattern and midlateral row of double dark brown spots forming rectangular markings. It has segmented and non branching caudal rays 3 (rarely 2), branching 14 (rarely 15). Predorsal cycloid scales 7-10, trunk ctenoid. Few with no black spots on nape. Isthmus narrow, scaled forward to vertical at posterior part of preoperculum. 2 diagonal, dusky lines on operculum; an inverted U-shaped spot prominent at the distal end of upper jaw. Pectoral fin with small dusky spots; 2 longitudinal lines on pectoral base spreading onto it fin rays. Sexual dimorphism exhibited in anal, pelvic and 2nd dorsal fin. Genital papilla of male sometimes darkly pigmented and reaching to side of anal spine. Female genital papilla truncate, ending well before origin of anal fin.

Distribution

Indo-West Pacific: Persian Gulf and Red Sea to Samoa, north to Taiwan, south to Lord Howe Island.

Habitat

A common species that inhabits areas of coralline sand of clear lagoon and seaward reefs. It is found singly.