Blackbar Filefish

Body and head color variable. Blackish to dark bluish branchial blotch extending dorsally to level well above the lower margin of eye and may include ventrally the pectoral fin base and axil. Iris usually dark brown. Orange to red caudal fin soft dorsal and anal fins clear, orange or yellow with spots; pectorals clear. Scale spinulation at midbody closely packed. Male scale ridge rugosities develop at about 80 mm SL developed. Strong first dorsal spine. Large pelvic fin rudiment narrowly attached to posterior margin of ventral flap.

Dorsal spines (total): 1 - 2; Dorsal soft rays (total): 29 - 34; Analspines: 0; Analsoft rays: 26 - 30

Occurs in shallow lagoons and seaward reefs to a depth of about 15 m; common in coral-rich areas. Secretive species (Ref. 9710, 48637) among rocks, sponges or in crevices on the bases of large coral formations. Adults usually form pairs but often only one is observed while the other one is hiding (Ref. 48637).

分布於印度-西太平洋區，西起非洲東岸，東至薩摩亞，北至日本南部，南至澳洲、新加勒多尼亞及東加。台灣南部、東北部、澎湖、小琉球、綠島及蘭嶼有分布。

小型魚類，較為常見，但無經濟價值。或以其可愛的模樣而常被飼養於水族館中，供人欣賞。

體長橢圓形，側扁，尾柄短而高。口小，前位。鰓孔小，側位，稍傾斜。鱗片小，長形，具一列向後倒之棘，約一至七個。體側中央鱗片聚集，不易個別區別；恥骨特化鱗三對，大且具許多強棘，可活動。第I背鰭棘強壯，在眼前半部上方，棘側各具一列約10枚之明顯強棘。體色深褐色、黑褐色、綠褐色、橙褐色，或淡褐色且具許多深色斑，通常頭部及體前半部較體後半部色深，而體後半部絕不呈淡褐色；體具許多極小黑點，且排列成許多規則的水平縱線；鰓裂具一明顯黑斑。尾鰭紅黃色或橙色，具許多細橫紋。

主要棲息於珊瑚繁生的淺潟湖及面海的礁區，一般被發現於水深1-20公尺內的水域。生性害羞，極具穩密性。

The blackbar filefish (Pervagor janthinosoma) is a fish in the family Monacanthidae. It is found in the tropical Indo-Pacific from the coast of east Africa to Samoa, north to southern Japan and south to New South Wales and Tonga.

Occurs in shallow lagoons and seaward reefs to a depth of about 15 m; common in coral-rich areas.