Blue Banded Pualu

Color in life bluish grey with numerous yellowish brown spots which tend to form irregular longitudinal lines; head with narrow irregular stripes; behind eye a yellow spot; brown pectoral fins; base of caudal fin with white bar. Caudal spine large, 3 - 4.4 in head. Stomach gizzard-like. Differs from A. dussumieri by having vertical stripes instead of spots on the blue central area of the caudal fin, from A. mata by having a lunate caudal fin, and from A. xanthopterus by having plain brown to blue-grey pectoral fins (Ref. 1602). The white ring around the base of the tail varies in intensity and may occasionally be absent (Ref. 1602).

Dorsal spines (total): 9; Dorsal soft rays (total): 25 - 27; Analspines: 3; Analsoft rays: 24 - 25

Adults occur in outer lagoon and seaward reefs, usually seen in small groups and school in some oceanic locations (Ref. 48637). Benthopelagic (Ref. 58302). They feed primarily on the algal film covering compacted sand, ingesting the usual component of sand which probably aids in the trituration of the algal food in the thick-walled stomach, also feed on diatoms and detritus (Ref. 3921).

fisheries: commercial; aquarium: commercial

廣泛分布於印度-太平洋區，西起非洲東部，東至夏威夷及社會群島，北至日本，南至羅得豪島。台灣分布於北部、東北部、南部、綠島、蘭嶼及小琉球等。

一般以流刺網、一支釣、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。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；尾鰭彎月形，隨著成長，上下葉逐漸延長。體色一致為藍灰色，體側具有許多由暗黃褐色的小點所組成不規則的波浪狀縱線；頭部散布窄的且是不規則的黃褐色和藍色蠕蟲狀紋；臨近眼睛後方具有1個與眼約略等大之黃色斑塊。背鰭及臀鰭的鰭膜各具8-9條細藍縱線及橘黃縱帶；胸鰭一致為黃褐色至暗褐色；尾鰭一致為暗褐色，除了在基部有一白色橫帶；尾柄棘溝藍黑色。此魚種常被誤鑑為黑刺尾鯛(/Acanthurus mata/)。

主要棲息於潟湖外側、近潮池之礁區或礁砂混合區，棲息深度一般在12公尺以內，通常會形成一小群體或一大族群的方式出現。以攝取被沙土覆蓋的附著藻類為食，這種攝取一般沙子成分的行為，可能是要在薄的胃壁裡幫助磨碎海藻等食物。此外也以矽藻或有機碎屑為食。

Acanthurus blochii (ringtail surgeonfish) is a marine reef tang in the fish family Acanthuridae. The fish grow to a maximum length of 45 cm (18 in). It lives in the Indo-Pacific, with a depth range from 2–15 meters deep. Adults can be found in outer lagoons and seaweed reefs, in small groups, and feed on algae.

Occurs in outer lagoon and seaward reefs to a depth of over 12 m and feeds primarily on the algal film covering compacted sand.