T. melanochir (Bleeker) is a synonym based on the terminal male of Thalassoma amblycephalum, with initial phase fish being far more numerous than terminal males.
Details
§ 01
size
Max. 17 cm
color
Initial phase with broad black stripe through eye to upper caudal. Green above, cream below. Caudal margins broadly orange. Terminal males purplish. Head blue. Nape yellow. Two fine oblique gold lines on cheek.
This species is typically found in groups in shallow reefs, up to a depth of 15 meters. Its diet consists mainly of zooplankton that it finds in the water column above the seafloor.
distinctive characters
This fish has a dorsal fin with 8 spines and 13 rays, an anal fin with 3 spines and 11 rays, a pectoral fin with 15 rays, and a body depth of 3.8-4.2 inches in standard length. Additionally, there are no scales dorsally on the opercle, and the caudal fin is truncate to slightly emarginate, becoming lunate in large males.