Acanthurus tennenti is a fairly common shallow water surgeonfish whose sides can range in color from very pale brown, when the black "ear-stripes" stand out very clearly, to a very dark brown, when they are almost invisible.
Details
§ 01
size
Max. 31 cm
color
Brown. Black marks behind eye: horseshoe-shaped in juveniles but becoming two separate stripes in adults. Caudal fin with white margin. Black area around caudal spine edged with pale blue.
This species can be found on coral reefs at depths of up to 20 meters, where it forms small schools and grazes on benthic algae.
distinctive characters
The dorsal fin has nine spines and 23-24 rays, the anal fin has three spines and 22-23 rays, and the pectoral rays are sixteen. The body depth is 1.9-2.2 times the standard length, and it becomes more elongated as the size increases.