Species: Ctenogobius claytonii, Mexican Goby

Ctenogobius claytonii (Meek, 1902)

Mexican Goby

Elongate, compressed body; snout round; eyes large, towards front, narrow between them; 2 pores behind eye, last one on preopercle; jaws long in male, not reaching under rear edge of eye in female; tongue truncate or slightly indented at tip; teeth in upper jaw in several rows, outer row in males enlarged, less so in females, 4-6 rows at front of jaw; lower jaw with several rows of teeth, strong recurved canines along side of lower jaw; 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, third spine long and filamentous, + I, 11 (10-12); length of 2nd dorsal base > distance from 2nd dorsal base to tail fin; anal fin I, 12 (11-13); pectoral fin 16 (15-18); pelvic fins I, 5, united forming a disc; tail fin long and pointed; scales 34 (29-39) in lateral series, scales rough near tail base becoming less rough near head, head scaleless; no lateral line.

Generally, very lightly pigmented; a bar from eye to mid-side of jaw; cheek dusky with poorly defined markings; edge of preoperculum not distinctly darker; top of head uniformly pigmented to vaguely mottled, with 4 narrow dark bars on nape; trunk with 5 narrow irregular bars (not V shaped) on upper flank; tail fin in males with a dusky region over lower ½ which is divided by a clear submarginal stripe; upper 1/2 faintly barred and dark elongate spot at upper edge near base; females with lower margin dusky and remainder of fin with vertical bars; pelvics dark in male, striped in female.

Reaches: 7.9 cm.

Habitat: In streams and estuaries; fresh to brackish water.

Depth: 1-10 m?

SW Gulf of Mexico.