Body depth distinctly less than head length, depth contained 2.7 to 3.1 times in standard length (for fish 13 to 20 cm standard length); caudal-peduncle depth 10.6 to 11.8% of standard length. Eye diameter slightly greater than snout length, contained 4.3 to 4.7 times in head length; preopercle rounded, the rear edge distinctly serrate with a large spine (usually hidden by skin) directed downward and forward at the “angle.” Gill rakers 6 to 8 on upper limb, 14 to 16 on lower limb, 20 to 23 total. Dorsal fin with XI spines and 18 to 20 rays; anal fin with III spines and 9 rays; pectoral fins with 17 to 19 rays; caudal fin rounded. Scales smooth; lateral-line scales 54 to 62; lateral-scale series 67 to 75.
Colour: Head and body brownish, with small dark spots forming horizontal streaks posteriorly and extending onto soft dorsal and caudal fins; pectoral fins pale, with 5 or 6 broad, dark crossbars, which are darker and more distinct distally.

Eastern tropical Pacific from northern Gulf of California to Panama.

Presumably like that of the other two species (see "Ecology" under the genus description). Johnson and Keener (1984) have described and illustrated the dorsal- and pelvic-fin spines of the larvae and compared them with Alphestes immaculatus and A. afer.

Maximum total length about 25 cm.