The Black Triggerfish, Melichthys indicus, can be easily distinguished from its similar counterpart, M. niger, by its tail shape and color; M. niger has an emarginate caudal fin that is entirely dark.
Details
§ 01
size
Max. 25 cm
color
Dark, almost black. White along bases of second dorsal and anal fins, and around caudal margin. Sometimes displays a rust brown patch behind spiny dorsal.
This species is typically located in coral reef habitats and appears to feed on zooplankton from higher up in the water column.
distinctive characters
The fish has a dorsal fin with three spines and thirty to thirty-four rays, an anal fin with twenty-nine rays, a pectoral fin with fourteen to sixteen rays, and a caudal fin that is truncate or slightly rounded, with ridges on the caudal peduncle not being prominent.