Tigrigobius janssi (Bussing) 1981
photo from Allen & Robertson 1994

IDENTIFICATION

Head Pores - Cephalic canal system with pores B',C,D,E,F,H'; preopercle pores M',N'

Scales - No scales present except for two small basicaudal scales.

Fins - D1- VII, no spines filamentous; D2 10(9-11); pectoral 17-18(16-19); anal 9(8-10); caudal segmented 17(16-17); pelvic I,5 all rays branched, disk complete, elongate, reaching 3/4 distance to anus.

Head - No rostral frenum; maxilla extending past posterior of eye by about 3/4 the eye diameter; anterior nostral a wide erect tube, posterior nostral a raised rim; interorbital narrow, about puil diameter.

Papillae - A reduced transvers pattern, typical of Tigrigobius and Elacatinus; three rows anterior of row b; row 5i/6i at anterior of row b and not extending below the level of row d; no vertical rows extend below the level of row d; row d divided into two sections;

Color - From Bussing(1981): Color of live and preserved material similar. Ground color pale, dorsum with four longitudinal rows of brown spots subequal to pupil diameter; dorsum and sides of head with irregular brown blotches. Mid-dorsal series of 15 spots between nape and caudal fin base; first three spots laterally elongate on predorsal region; spots on base of dorsal fins in pairs of closely approximated spots separated from succeeding pairs by wider and palerer interspaces; last four spots on caudal peduncle less distinct. An upper dorsolateral series of 19 spots extending from above opercle to caudal base. A lower dorsolateral series of about 13 spots sometimes merging posteriorly with upper dorsolateral spots. A series of about 11 spots on lateral midline extending from behind pectoral fin base to caudal base. A V-shaped mark, half covered by opercle, on pectoral fin base; a spot on proximal portion of pectoral rays 3 to 7 and a matching spot on axillary side of fin; remainder of fin clear. A dark transverse bar on base of caudal fin. Dorsal and anal fins dusky on distal half; pelvic fin disk dusky; caudal fin clear. An internal vertical bar pattern on peritoneum and median skeletogenous septum visible through muscle wall of live specimens and of small preserved individuals; two elongate blotches on peritoneum, two bars extending between dorsal and anal fin bases and a third bar between rear base of dorsal fin and ventral margin of caudal peduncle. (Bussing 1981) head yellowish with brown bar below eye, and brown bands and spots on cheek and opercle; body translucent pale yellow to whitish, with small brown spots on upper half, body with 6-7 internal, wavy, brown bars. (A&R 1994)

Distribution - Costa Rica; between Bahia Salinas in northwestern Costa Rica and Isla del Cano in southern Costa Rica (Bussing 1981); Costa Rica and Panama (A&R 1994)

Habitat - Common over sand and gravel bottoms associated with rocky reefs. (Bussing, 1981) inhabits reefs and rock outcrops surrounded by sand (A&R 1994); 0.5 - 21 meters; common in depths greater than 5 meters (Bussing, 1981)

Notes -