Species: Gillichthys detrusus, Delta mud-sucker

Gillichthys detrusus Gilbert & Scofield, 1898

Delta mud-sucker

Moderately elongate, body compressed; head large (> 25% TL) broad, flattened, upper head profile depressed, ~straight; snout flat, tip very blunt; sensory papillae on head small, crowded, numerous; eyes on upper sides of head, directed upwards; mouth ~ horizontal, opens at front; jaws very long - lower extends ½ way to gill opening, upper to pectoral fin; preopercle covered with skin; teeth small, conical, 4-5 rows on each jaw; first dorsal fin low and rounded, VI (IV-VIII); 2nd dorsal fin I, 11-12; anal fin with short base, I, 10-11; pectoral broad, rounded, usually 22 or more rays, top ray not partly free from fin; pelvics form disc, membrane between pelvic fin spines without side lobes; tail rounded; scales small (~ 90 rows along side), imbedded, rough in juveniles, mainly smooth in adults; narrow strip of non-overlapping imbedded scales on top of nape; scaled space between dorsal fins ~1/2 length of 1st dorsal fin base; skin covered with thick mucous.