Black Surgeonfish

A horizontally elongate white blotch directly below eye. No orange band in outer part of dorsal fin. Caudal peduncle black except for yellow edge of socket and sheath of peduncular spine. Base of pectoral fin black (ref 9808).Gill rakers on anterior row:17-19, on posterior row:18-20.Description: Characterized further by blackish or dark grey body color; white patch below eye; white ring behind mouth; base of dorsal and anal fins with yellow zone that gradually widens towards rear part of fins; caudal spine yellow; caudal fin yellow with submarginal band; caudal spine length 2.5-3.0 in head length; greatest depth of body 1.7-1.9 in SL (Ref. 90102).

Monogamous mating is observed as both facultative and social (Ref. 52884).

Dorsal spines (total): 9; Dorsal soft rays (total): 28 - 31; Analspines: 3; Analsoft rays: 26 - 28

Inhabits hard substrate areas of clear lagoon and seaward reefs from the lower surge zone to at least 67 m and feeds on filamentous algae (Ref. 58534, 58652). Monogamous (Ref. 52884, 48637). Small juveniles shy among large corals (Ref. 48637). A territorial species. Roving herbivore (Ref. 57615).

Adults inhabit hard substrate areas of clear lagoon and seaward reefs from the lower surge zone to at least 67 m and feeds on filamentous algae. Solitary or in groups (Ref. 90102). Monogamous (Ref. 52884, 48637). Benthopelagic (Ref. 58302). Small juveniles shy among large corals (Ref. 48637). Territorial species. Common throughout Micronesia and hybridizes with the rare A. achilles. Size of metamorphosis from the postlarva stage to juvenile is 5.5 to 6 cm (Ref. 9267).

fisheries: subsistence fisheries; aquarium: commercial

分布於泛太平洋區，包括太平洋之熱帶島嶼及東太平洋地區。台灣分布於南部、東北部、及東部離島等。

一般以流刺網、延繩釣或潛水鏢魚法等捕魚時之意外獵物。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。頭小，頭背部輪廓不特別凸出。口小，端位，上下頜各具一列扁平齒，齒固定不可動，齒緣具缺刻。背鰭及臀鰭硬棘尖銳，分別具XI棘及III棘，各鰭條皆不延長；胸鰭近三角形；尾鰭近截形或內凹。體黑褐色；眼睛下緣具一白色斑駁，不向下斜走至上頜；吻部另具半月形白斑。背鰭及臀鰭黑色，基底具一黃色紋，向後漸粗，鰭緣為淡藍色；尾鰭淡灰白色，內側具橘黃橫帶，鰭緣為淡藍色；胸鰭基部黑色，餘灰黑色，上緣淡藍色；腹鰭黑色，鰭緣為淡藍色；尾柄棘溝緣為黑褐色，但尾柄棘為黃色。

主要棲息於清澈而面海的潟湖及礁區，棲息深度由浪拂區至65公尺左右。領域性強。以絲狀藻類為食。

The whitecheek surgeonfish, also known as the goldenrim surgeonfish or yellow-spotted surgeonfish (Acanthurus nigricans), is a reef-associated tang found from the central Indo-Pacific area to the eastern Pacific coast, Hawaii included. It occasionally makes its way into the aquarium trade. It grows to 21.3 cm in length.