Elegant Unicornfish

Naso elegans, commonly known as the elegant unicornfish, is a species of marine fish belonging to the family Acanthuridae, which includes surgeonfishes, unicornfishes, and tangs. This species can be found in the 🇮🇳 Indian and western 🌊 Pacific Oceans.

First described in 1829 by German zoologist and explorer Eduard Rüppell, Naso elegans was initially classified as Aspisurus elegans. Its type locality is recorded as the northern 🌊 Red Sea. The species falls within the nominate subgenus of the Naso genus, which is the sole genus in the subfamily Nasinae within the Acanthuridae family. While previously believed to be an 🌊 Indian Ocean color variant of the orangespine unicornfish (Naso lituratus), studies have revealed consistent meristic differences between the two.

The specific name elegans is derived from the Latin word for "choice," "fine," or "select," which alludes to the beautiful colors exhibited by this fish.

Naso elegans possesses six spines and typically 28 soft rays, although the number can range from 26 to 30, in its dorsal fin. The anal fin is supported by two spines and typically 29 soft rays, with a range of 27 to 30. The pectoral fin contains either 16 or, more commonly, 17 fin rays. Each jaw of Naso elegans has between 30 and 35 teeth, resembling incisors with rounded edges in adult specimens. As the fish matures, its body becomes more elongated, with a depth equivalent to approximately one-fourth of the standard length. Males exhibit larger keels on the caudal peduncle and longer filaments growing from the caudal fin compared to females. The overall body coloration is gray, with a yellow bar at the eyes separating the dark snout from the gray head. The dorsal fin is yellow with a thin blue edge and a black band internally. The anal and pelvic fins are dark brown. The plates on the caudal peduncle are vivid orange, bordered by a white patch. The caudal fin is yellowish, with a black submarginal band and upper and lower black edges. Typically, the elegant unicornfish reaches a maximum total length of 45 cm (18 in), although 35 cm (14 in) is more common.

Naso elegans is distributed throughout the 🇮🇳 Indian and 🌊 Pacific Oceans. Its range extends from the 🌊 Red Sea along the eastern coast of Africa to Durban, 🇿🇦 South Africa, and across the 🌊 Indian Ocean to Bali (🇮🇩 Indonesia), 🇮🇩 Indonesia, and other areas in the Pacific. Notably, it is absent from the waters off the mainland 🇮🇳 Indian subcontinent. In 🇦🇺 Australian waters, it has been documented in Christmas Island and the Cocos (Keeling) Islands. The elegant unicornfish is known to inhabit reef flats in coastal and inshore waters, where it forms small schools. In more oceanic environments, it can form larger schools.

As a herbivore, Naso elegans primarily feeds on benthic algae, particularly species of Sargassum and Dictyota, which are brown algae.