Species: Ctenogobius phenacus, Impostor Goby

Ctenogobius phenacus (Pezold & Lasala, 1987)

Impostor Goby

Body elongate, slightly compressed; head rounded; eyes large, towards front, narrow between them; jaws long, reach under rear edge of eye; tongue slightly emarginated; teeth in upper jaw in 2 rows, outer row enlarged, cone shaped and fewer than those of inner row; lower jaw in males with 2-3 rows and 2-3 large partially recurved canines on each side, females with a fine band of teeth in lower jaw and a single tusk-like tooth in outer row on each side in large specimens, a few heavy teeth on either side of middle of jaw in inner row; front of roof of mouth without teeth; gill rakers short, triangular 0 + 4-5; gill membranes broadly joined to body under throat, with 5 rays; dorsal fin VI + I, 11 (10-11); length of 2nd dorsal base > distance from 2nd dorsal base to tail fin; anal fin I, 12 (11-12); pectoral fin 18 (17-19); pelvic fins I, 5 united forming a disk, anterior membrane with small finger-like projections along each edge; tail fin very long and pointed (at least 42% of SL in male, at least 39% in female); scales rough, 29 (29-34) in lateral series; no lateral line.

A dark stripe across midcheek from preopercle to corner of jaw; a bar from eye to middle of upper jaw, with spot on upper lip; top of head crossed by several bars; opercle with dusky patch; preopercle edge not distinctly darker; a dark patch on body behind upper angle of opercle; 5 midlateral blotches on trunk, with diagonal dorsal arms forming a V pattern in adults; 1st dorsal with 2 diagonal stripes, second dorsal with submarginal stripe and sometimes with pigment on bases of rays; pectoral fins dusted; pelvic fins generally clear; anal fin clear; tail fin lightly sprinkled with small spots along rays.

Reaches: 3.2 cm.

Habitat: shallow waters of estuaries.

Depth: 0-3 m.

Distribution: Venezuela to French Guiana.