Body deep, oval, greatest body depth 1.8-2.2 in SL; 1 pair of nostrils; edge of bone under eye smooth; preopercle smooth or with occasional fine serrations; mouth short, protrusible, oblique, opens at front; teeth in 2 rows, outer conical, larger; gill rakers 27-31; a single continuous dorsal fin, XIII, 11-12; anal II, 11; pectoral rays 18-19; 2-3 short projecting spines at upper and lower base of tail fin; tail forked, rounded tips; scales large and rough; 15-18 lateral line scales; body scaled, most of head scaled, basal parts of the median fins scaled; lateral line incomplete, ends under end of dorsal fin base.
Bluish grey with a largely bright blue head and with yellow dorsal, caudal, and anal fins; yellow coloration of dorsal fin usually continuous with pale yellowish or whitish caudal peduncle; juveniles largely bright blue on anterior two-thirds and bright yellow posteriorly, the yellow region confluent with yellow dorsal, tail, and anal fins.
Maximum size to 12 cm.
Inhabits rocky shores.
Depth: 5-75 m.
The lower 2/3 of the Gulf of California, and the Revillagigedos islands.