Lined Unicornfish

Naso brevirostris, commonly known as the short-nosed unicornfish, is a distinct member of the Acanthuridae family, which includes surgeonfishes and tangs. This species is found throughout the 🇮🇳 Indian and western 🌊 Pacific Oceans, including regions from the 🌊 Red Sea and East Africa to the Hawaiian and Pitcairn Islands, and extending in 🇦🇺 Australia from Ningaloo Reef to Moreton Bay. First described in 1829 by French zoologist Georges Cuvier, it's believed to originate from 🇮🇩 Indonesia.

The short-nosed unicornfish is named for its shorter snout compared to related species like Naso fronticornis. Its body is characterized by six spines and 27 to 29 soft rays on the dorsal fin, and two spines with the same number of soft rays on the anal fin. Its physical appearance includes a distinctive abrupt, steep snout and elongated bony growths above the eyes, which can reach the length of the head as the fish matures. It also features bony plates on each side of the caudal peduncle, with the caudal fin varying from flat to slightly rounded.

Coloration varies, ranging from light blue-grey to olive-brown, with an alternate pale frontal quarter contrasted by the rest of the body. Vertical dark grey lines transition to spots along the flanks, while the head may have small dark spots or a lattice pattern. A bony protrusion features diagonal black lines, complemented by a white operculum membrane, pale blue-edged lips, and a mostly whitish caudal fin. The fish can grow up to 60 cm (24 inches) long.

Inhabiting lagoon and seaward reefs, Naso brevirostris is typically found at depths of up to 46 meters (151 feet). It forms spawning groups and tends to pair spawn, with males displaying more prominent caudal peduncle keels than females. The eggs develop into pelagic larvae that can live up to 90 days before maturing, usually when the fish is around 25 cm (9.8 inches) long. As they grow, their diet shifts from benthic algae to mainly gelatinous zooplankton, corresponding with the development of their bony protrusion.

While Naso brevirostris is often caught for food using methods like fish traps and spearing, caution is advised due to occasional Ciguatera fish poisoning cases linked to its consumption.