Common names: flounder (English), lenguado (Espanol)
Etropus peruvianus Hildebrand, 1946
Body relatively slender (height 34-45% of SL); head blunt, short, length 25-29% of SL; eyes on left side, eyes ~ parallel, upper eye below edge of head, with crest behind it; mouth very small, 21-25% of head, ends under front edge of pupil; jaws on blind side arched; most of teeth on blind side, in 1 row on each jaw, none enlarged; lower gill rakers 5-9; dorsal rays 79-86; anal rays 62-68; base of eye side pelvic on midline of body, 6 pelvic fin rays; pectoral fin 80% of head length; tail fin with blunt angular point; urinary papilla on blind side, immediately behind anus; lateral line starts at top corner of operculum, relatively straight; scales small, rough, easily dislodged, without small accessory scales; 41-48 lateral line scales.
Eye side grey-brown, large dark blotch behind operculum that extends back along lower flank behind pectoral, fins paler than body, with dark speckles, pectoral with outer 1/3 dark; blind side pale.
Size: 10 cm.
Habitat: shallow soft bottoms.
Depth: 0-45 m.
The Gulf of California to northern Peru.