Dead specimens of Heniochus acuminatus can be identified by counting the number of dorsal spines, which is 11, while H. diphreutes has 12. Living specimens may be distinguished by their snout shape, fin patterns, or habits (see overleaf).
Details
§ 01
size
Max. 23 cm
color
White with two diagonal stripes. Dorsal, caudal and pectoral fins yellow. Anal spines black.
Typically seen alone or in pairs close to the seabed, this species feeds on zooplankton and benthic invertebrates.
distinctive characters
This fish has a dorsal fin with 11 spines and 24-27 rays, an anal fin with 3 spines and 17-19 rays, a pectoral fin with 15-18 rays, and a body depth of 1.2-1.4 in standard length. Additionally, the fourth dorsal spine is extremely elongate, and large adults have a short stout spine in front of each eye.