Blackblotch foxface, One-spot foxface
The blotched foxface (Siganus unimaculatus), also called the blackblotch foxface or one-spot foxface, is a species of marine ray-finned fish, a rabbitfish belonging to the family Siganidae. It is found at reefs and lagoons in the central Indo-Pacific. Except for the black spot on the rear upper body, it resembles the closely related foxface rabbitfish.
The blotched foxface has a compressed body which has a depth which fits into its standard length 1.9 times. The dorsal profile of the head is steep to the rearof the eye and there is an indentation between the eyes. The caudal fin is forked. Like all rabbitfishes, the dorsal fin has 13 spines and 10 soft rays while the anal fin has 7 spines and 9 soft rays. The fin spines hold venom glands. This species attains a maximum total length of 20 cm (7.9 in). This species is bright yellow with the head and front part of the body being white with a black band running from the mouth to the start of the dorsal fin and another black band extending from the shoulder to the chest. There is an irregular black spot or blotch on the centre to rear of the upper flanks.
The blotched foxface has two disjunct populations: a northern population which is found in the Western Pacific Ocean from the Ryukyu and Ogasawara Islands of Japan to the Philippines, and a southern population which is restricted to the Rowley Shoals in the Timor Sea off northwestern Australia. This species is found in shallow waters down to 14 m (46 ft) on coral reefs made up of Acropora and Porites, and also on coral rubble.
The blotched foxface is herbivorous and feeds on seaweeds. Adults an subadults live in pairs, including same-sex pairs; the adult pairs seem to be permanent. Reproduction appears to takes place at the new moon when large aggregations occur and the demersal eggs are laid. Juveniles may gather in large schools. This species produces venom in the spines of its fins. In a study of the venom of a congener it was found that rabbitfish venom was similar to the venom of stonefishes.
