Common names: goby (English), gobio (Espanol)
Microgobius brevispinis Ginsburg, 1939
Balboa goby, Short-spine goby
Head and body compressed; fleshy crest on nape in one sexes; 2-3 pores on preopercle; mouth large, nearly vertical; 6-7 pairs of large canines on lower jaws; tip of tongue divided; dorsal fin VII (spines relatively short) + I, 16-19 rays; anal I, 16-19 rays; pectoral fin relatively short (22% of SL), 19-22 rays; tail fin long, oval or pointed (in males); pelvics fused to form disc; all scales smooth, from below 3rd dorsal spine rearwards on body, in 63-81 lateral rows.
Both sexes: grey brown, base of tail (behind anus) paler than body; three oblique blue bars separated by orange on operculum; two blue spots separated by orange on pectoral base; pelvics blackish, with white margin. Male: a dark blotch with a blue bar behind it under anterior dorsal spines; back behind anus with a blue stripe above, and (sometimes) 2 orange spots below; first dorsal with a black spot on first spine, red outer margin; second dorsal dusky, with red spots at lower rear and a yellow oblique central stripe; tail fin with red spots above, a red central stripe and yellow below; anal fin dusky. Female: intense orange bar bounded in front by blue bar and two orange spots on body under the first dorsal fin; a short blue bar on midside just behind anus.
Size: 8.2 cm.
Habitat: beaches and tide pools with muddy shell bottoms in estuaries.
Depth: 0-6 m.
Southern Baja and the eastern Gulf of California to Panama.