Species: Idiastion hageyi, Galapagos humpback scorpionfish

Idiastion hageyi McCosker, 2008

Galapagos humpback scorpionfish

Body behind head deep, humpbacked, compressed; head very bony, with strongly developed spines, often with multiple points, numerous large spines on top of head and nape; without pit behind eyes; head profile moderately steep; eye large, with a row of papillae nearly surrounding it; front nostril with a slender tentacle, slightly shorter than nostril tube; longitudinal ridge under rear of eye with 5 spines; uppermost  of 4 preopercular spine separated from others and longest; teeth small, simple, on sides and front of roof of mouth; small slit behind last gill arch; mouth large, slightly oblique; lower jaw slightly protruding with a front knob; in throat; dorsal fin XII (3rd spine longest, 9 branched rays; anal fin III, 6 branched rays; pectoral with longest rays in center, 18 rays, ray 1 & bottom 7-9 rays unbranched, lower, unbranched rays fleshy, with free tips; scales mostly rough; between eyes without scales; lateral line complete, with tubes on scales, 15-16 pored scales; 52 scale rows in longitudinal series; small swim bladder.