Microgobius brevispinis Ginsburg 1939

Photo by Thorsen and Van Tassell

top: female
bottom: male

IDENTIFICATION Head Pores - Supraorbital canals seperate most of their extent; oculoscapular canal with pores B',D,F,G,H'; preopercle canal with two pores. Scales - Lateral scale rows 63-81, scales entirely cycloid, no ctenoid patch beneath the pectoral fin; scales extending forward to a point about even with third dorsal spine; scales absent on dorsum immediatley below anterior half of the spinous dorsal fin;

Fins - D1 --18[16-19], second through fifth dorsal spines filamentous in males, extending past caudal base in large specimens, spines little extended in females; anal 18[16-19]; pectoral fin - 21[19-22];

Head - Gill rakers on forst arch 4+16; dentary with 6-7 teeth in outer row; fleshy nuchal crest moderately developed in both sexes;

Papillae - A transverse pattern: Row b long, extending forward to under middle of eye and uniting atthe anterior end with a vertical transverse row; row d continuous; vertical rows not extending below level of row d; row x continuous along lateral edge of head from behind the eye to above the pectoral fin base; row n continuous across the dorsal surface of the head.

Color - In freshly preserved specimens: Body of males yelowish green above, pale yellow below; sides under pectoral mottled with iridescent blue and yellow spots; an intense dark bar bordered in orange-yellow on body just above the pectoral fin; head and operculum with four horizontal orange-yellow lines with iridescent blue lines between; branchiostegal membranes yellowish; pectoral base with three yellow-orange horizontal lines with iridescent blue lines between; spinous dorsal fin with two yellow-orange stripes and yellowish distal margin; soft dorsal fin with yellowish base, a median orange-yellow stripe and orange-yellow distal margin; pectoral fins uniformly pale; pelvic fins dusky; anal fin dusky with medial orange-yellow stripe which is continuous with similar stripe on caudal fin; caudal fin yellowish with yellow-orange longitudinal stripe on lower half and an intense orange spot at the base of dorsalmost rays.

       In females body greenish yellow above, pale below; the areas being sharply defined by a narrow stripe originating at the origin of the anal fin and running posterodrsad to the median line and continuing to the caudal base but becomming faint posteriorly; an intense irisdescent yellow bar above and under pectoral fin; head and pectoral base as in males; spinous dorsal fin pale with orange-yellow distal margin; soft dorsal fin with three disky yellow stripes, one basal, one medial and one distal; pectoral fins pale; pelvic fins dusky with dusky-yellow border; anal fin dusky with pale distal margin; caudal fin yellowish with orange spot on base of dorsalmost rays. (Birdsong 1981)

Distribution - Known from Baja California and the northern Gulf of California to the Pacific coast of Panama.

Habitat - Found in tidepools and beaches with a muddy shell bottom; frequently occurs with Microgobius emblematicus.

Notes - This species is the largest in the genus.