Trachinotus anomalus Temminck & Schlegel, 1844 The Pacific rudderfish (Psenopsis anomala) is a marine fish also known by such names as Japanese butterfish, melon seed, wart perch, ibodai (Japanese name, イボダイ) or simply but ambiguously as butterfish.

[1][2] This fish, which can grow to 30 cm (12 in) TL, is found in the Western Pacific, near Japan, in the Taiwan Strait and in the East China Sea.

Some other features of this fish are a robust snout, a relatively small mouth, and the upper jaw extending to below the anterior margin of the eye.

[3] This species is of economic importance, commercially sought after, and caught by trawl by Japanese and Taiwanese fishermen.

In Tokushima, a regional cuisine, bōze no sugata sushi (ボウゼの姿寿司), is made with Japanese butterfish.