Stellate Rabbitfish

Siganus stellatus, commonly known as the brown-spotted spinefoot, is a marine fish species belonging to the family Siganidae. It is primarily found in the Indo-Pacific region.

Characterized by its deep and laterally compressed body, Siganus stellatus has a body depth that is 2 to 2.3 times its standard length. The head has a nearly straight dorsal profile with a 45° angle between the forehead and the snout, while the ventral profile has a slight indentation under the chin. In adults, the front nostril has a low rim, whereas juveniles have a long triangular flap. The dorsal fin has 13 spines and 10 soft rays, while the anal fin possesses 7 spines and 9 soft rays, with venom glands present in the fin spines. As the fish grows, the caudal fin transitions from emarginate to deeply forked. Siganus stellatus typically reaches a maximum length of 40 cm (16 in), although 35 cm (14 in) is more common. The body features a honeycomb pattern created by small dark brown to black spots densely covering a white background. The fins also have black spots, and the caudal fin and rear edges of the dorsal and anal fins have a whitish margin. A light, whitish to yellowish saddle mark on the caudal peduncle is often observed. In the subspecies S. s. laqueus, the body has a greyish green background color with dark brown spots covering both the head and body.

Geographically, Siganus stellatus is found in the 🌊 Red Sea, 🌊 Indian Ocean (extending as far south as 🇿🇦 South Africa), and the 🌊 Pacific Ocean (reaching 🇸🇬 Singapore). In 🇦🇺 Australia, it is solely recorded in the Cocos (Keeling) Islands. This species inhabits seagrass beds, seaward reefs, and lagoons, typically at depths ranging from 1 to 30 m (3 ft 3 in to 98 ft 5 in). Juveniles have been known to venture into weedy estuarine habitats.

Feeding primarily on benthic macroalgae, Siganus stellatus typically lives in pairs as adults, whereas subadults and juveniles form schools. Breeding patterns indicate some seasonality, with peaks of juvenile numbers occurring during summer. It is worth noting that this species produces venom in its fin spines. In a study comparing the venom of a related species, rabbitfish venom was found to resemble that of stonefish.