Gobiosoma paradoxum

top: female photo by J.Van Tassell
bottom: male photo by Thorsen & Van Tassell

IDENTIFICATION

Head Pores - Cephalic head pores with pores B',C,D,E,F,H' and preopercle pores M',N,O'

Scales - Basicaudal scales present 4[4-6], with enlarged ctenii; caudal peduncle completely scaled up to the seventh ray of the second dorsal, than becoming wedge shaped ending under the middle ofthe first dorsal to origin of second dorsal; an isolated patch of scales under pectoral fin.

Fins - D1 - VII, elongate in larger males; D2 - 12[12-13]; anal 10[10-11]; pectoral rays 17-18[16-19]; caudal segmented rays 17[16-17]

Head - Head rounded; mouth oblique; maxilla reaching to middle or end of pupil; interorbital narrow, less than 1/2 eye diameter; gill rakers on first arch slender 9-11[8-13]; no barbels; small protuberance on preorbital rim below the anterior nostril;

Papillae - A transverse pattern; three rows in front of the anterior end of row b; row 5i/6i united and under the middleof row b; row b extending below the level of row d; first three vertical rows not extending below the level of row d.

Urogenital papilla - males - slender, not bilobed

Color - Color in alcohol (from Hoese 71) Background of head and body tannish brown or dark brown. A small faint black spot behind eye, a small faint black spot at upper and posterior margin of preoperculum, and a small spot at upper and posterior margin of operculum.

MALES: Dorsal surface of head and cheeks and dorsal and anterior half of body lighter than rest of body. Two faint dark bands across dorsal surface of head. Body with 5 to 7 faint uniformily pigmented. MALES: Dorsal surface of head and cheeks and dorsal and anterior half of body lighter than rest of body. Two faint dark bands across dorsal surface of head. Body with 5 to 7 faint uniformily pigmented transverse bands discernible on dorsal surface of body, oftyen obscure. Midside with or without a series of short black dashes. Fins black; lighter specimens with 3 black bands across first dorsal fin; 2 black longotudinal bands on second dorsal fin; anal fin darkest near white tip; pelvic fin margin white; first dorsal spine white. Chest with melanophores. Urogenital papillae densely covered with melanophores except on anterior face of tip. (Hoese, 1971)

FEMALES: Dorsal surface of head and cheeks and the dorsal and anterior half of body sometimes lighter than the rest of body. Two oblique black bands extending from lower margin of eye across ventral surface of lower jaw. An oblique black band on lower part of preoperculum and a similar on lower part of operculum; both bands extending acreoss throat. Body with 6 to 8 granular transverse bands; central part of band on midside with short black dashes. Fins clear to dusky; dorsal with three longitudinal black bands; caudal fin with 6 to 7 wavy transverse bands;pectoral fin clear or with faint wavy transverse bands; pelvic clear or with 2 faint longitudinal bands. Chest without melanophores in adults. Urogential papilla with a few scattered malanophores. (Hoese, 1971)

Distribution - Main land of Mexico (Guaymas to Santa Cruz), Costa Rica, Panama, Equador. Seale (1940) reported species from Espiritu Santo Island, Mexico, however the color pattern description does not fit paradoxum [Hoese 71] Rare in the Gulf of California according to Thomson et al 1979. Very common in Panama Bay area and in the Pacific side of the Panama Canal.

Habitat - Tidepool to subtidal, in rocky, sandy, and muddy bottom habitats; very common in Panama Bay and the Pacific side of the Panama Canal.

Notes -