Fins - D1 - VI, no spines filamentous; D2 - I,8; pectoral - 18(11-19); anal - I,8(I,8-I,9); pelvic fins seperate, no frenum present.
Head - Interorbital wide, 3 times eye diameter; maxilla extending to middle or rear margin of eye; anterior nostril tubular overhanging upper lip; posterior nostril an open pit.
Papillae - A transverse pattern with vertical rows 2 and 4 extending below the level of row d; opercle vertical rows os and ot' intersect on posterior opercle forming an acute fork opening towards posterior margin
Color - Preserved: dark tan or brown with darkest pigment laterally on trunk. Abdomen pale. Entire body often mottled. Two dark postocular stripes present, more distinct in young; uppermost postocular stripe extending horizontally from orbit to posterior opercluar margin; lower stripe extends to upper preopercular margin. Pigment on lateral scales may form dark bands, expecially in juveniles, continuous or broken into series of large blotches, band being formed from horizontal rows of spots; often with dark speckles on top of head highlighting longitudinal rows of free neuromasts. All fins posses wavy, dusky bands of spots. Dorsal and ventral spots sometimes present above and below hypural. (Pezold & Cage 2002)
Distribution - Common from Mexico to continental Ecuador and the Galapagos Islands, also from Cocos Island and Salton Valley of California (P&C 2002) A single specimen from San Juan de los Cayos, Falcon State, Venezuela - most likely from introduction in ship ballast water (P&C 2002)
Habitat - Freshwater streams to coastal, stagnent to fast flowing waters, inhabits streams to 100 m above sea level (Bussing 1998)