This rare fish is called Benten'uo or Pacific fanfish (Pteraclis aesticola) and recently (28-nov-2014) appeared  in Toyama bay, Japan. Is very rare and most likely seen as stomach content of large predatory fishes, such as tunas. Young probably inhabits shallow, adults deep water.

The species is silvery, blue-greenish to black with bright blue dorsal and anal fins. The genus name comes from the Greek word “ptera” meaning wing and “clis” meaning shut. The name refers to the impressive dorsal and anal fins of this species and presumably how they retract into scaly sheaths along the upper and lower margins of the fish. It grows to 61 cm in length.

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