Tetra a tall dorsal fin characterized by a short connection to the fish’s body. Additionally, tetras possess a long anal fin stretching from a position just posterior of the dorsal fin and ending on the ventral caudal peduncle, and a small, fleshy adipose fin located dorsally between the dorsal and caudal fins. This adipose fin represents the fourth unpaired fin on the fish (the four unpaired fins are the caudal fin, dorsal fin, anal fin, and adipose fin), lending to the name tetra, which is Greek for four. While this adipose fin is generally considered the distinguishing feature, some tetras (such
Apogonichthyoides pharaonis ridge and saw-like margin. There is a spine which projects from the operculum in line with the central point of the eye. There are three vertical black bars which contrast with the grey-brown ground colour of the body, there is one bar running down from each dorsal fin and the last bar is on the caudal peduncle. There is a characteristic black ‘eye-spot’ surrounded by a yellow ring within the first bar. The first dorsal fin has a dark leading edge while that of the pelvic fins is white. "Apogonichthyoides pharaonis" is native to the western Indian Ocean from the