Black Unicornfish

Inhabits clear lagoon and seaward reef slopes (Ref. 9710, 48637). Forms shoals. Mainly diurnal, it feeds on zooplankton such as crab larvae, arrow worms, pelagic tunicates, and occasionally filamentous red algae.

Dorsal spines (total): 6; Dorsal soft rays (total): 26 - 29; Analspines: 2; Analsoft rays: 27 - 30

This species is distinguished by the following characters: body moderately deep and compressed, its depth 2.6 to 3.2 times in standard length (SL); dorsal profile of body uniformly convex, without any bony horn-like projection or protuberance anteriorly on head; mouth small; incisiform teeth very small, somewhat pointed, finely serrate on edges, as many as 80 in upper jaw and 100 in lower jaw of large adults; continuous unnotched D VI (rarely V or VII),26-29; A II,27-30; pectoral-fin rays 17-18 (usually 17); pelvic fins I,3; caudal fin slightly emarginate in young, becoming truncate in adults; caudal peduncle slender, subcylindrical, with a pair of bony plates on each side that develop large sharp antrorse keels with age; body colour dark brownish grey, shading ventrally to yellowish (life colour may vary from dark brown to light blue-grey); edge of operculum and preopercle usually dark brown; dorsal and anal fins yellowish with faint diagonal brown bands and a blue margin; tongue black at lengths of 25 cm or more (Ref. 9808).

Hurleytrematoides Infestation 7. Parasitic infestations (protozoa, worms, etc.)

Lecithocladium Infestation 3. Parasitic infestations (protozoa, worms, etc.)

Prosogonotrema Infestation. Parasitic infestations (protozoa, worms, etc.)

Spawn in pairs (Ref. 240).

Inhabits clear lagoon and seaward reef slopes (Ref. 9710, 48637). Benthopelagic (Ref. 58302). Usually seen in large schools (Ref. 90102). Mainly diurnal, it feeds on zooplankton such as crab larvae, arrow worms, pelagic tunicates, and occasionally filamentous red algae. The species is never poisonous (Ref. 4795).

fisheries: commercial; gamefish: yes; aquarium: commercial

廣泛分布於印度-太平洋水域，西起紅海、非洲東部，東至馬貴斯及杜夕群島，北至日本，南至羅得豪島。台灣東部、西部、南部海域及離島之小琉球、蘭嶼、綠島均有記錄。

一般以流刺網、延繩釣或潛水鏢魚法等捕獲。觀賞及食用兼具。剝皮後，煮薑絲湯，肉質鮮美。尾柄上骨質盾板非常銳利，易傷人，處理時需小心。

體呈橢圓形而側扁；尾柄部有二個盾狀骨板，各有一個龍骨突。頭小，頭背弧形，隨著成長，成魚在前頭部無角狀突起，亦無瘤狀突起。口小，端位，上下頜各具一列齒，齒稍側扁且尖銳，兩側或有鋸狀齒。背鰭及臀鰭硬棘尖銳，分別具VI棘及II棘，各鰭條皆不延長；尾鰭截平或內凹，上下葉不延長。體背側褐色至藍灰色，體腹側黃色；鰓膜暗褐色；25公分以上之成魚，舌黑色。一般體側無任何斑紋，雄魚或許在頭部上部具有淡藍色斑塊，而體側前部另具有一些淡藍色橫帶或斑點。前鰓蓋骨及鰓蓋骨的邊緣為土黃色至暗褐色。尾鰭淺藍色或稍暗，末端具黃色緣。

喜棲息於清澈的潟湖區或外礁區斜坡，成魚常大群地一起在礁區及中表層游動。以動物性浮游生物為食，有時亦食紅藻。

The sleek unicornfish (Naso hexacanthus), also known as the blacktongue unicornfish or ʻopelu kala, is a tropical fish in the family Acanthuridae found in coral reefs in the Pacific and Indian Oceans. It is of value in commercial fisheries and as a gamefish, and is also seen in aquaria.

Inhabits seaward dropoffs, but usually found below 18 m. Forms schools. Mainly diurnal, it feeds on zooplankton, crab larvae, arrow worms, pelagic tunicates, and occasionally filamentous red algae. The species is never poisonous (Ref. 4795).

Known from seamounts and knolls