Threadfin tuna - Threadfin tuna

A marine fish of the order Perciformes, family Carangidae. It is widely distributed in the Pacific Ocean from central Honshu southward, and across Hawaii, Samoa, and the Indian Ocean, and lives along the coasts. It is caught in various parts of southern Japan using fixed nets and fishing. It reaches a total length of 90 cm, and its body is close to a rhombus, with large lateral compression. In the juvenile stage, the soft rays of the second dorsal fin and the front of the anal fin are thread-like and more than twice the total length, but they shorten as it grows. The ridged scales are small and only found on the straight part of the lateral line near the caudal peduncle. It is not highly valued as an edible fish, but the graceful way in which juvenile fish swim with their fins flapping makes them popular ornamental fish in aquariums.

[Kiyoshi Suzuki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

硬骨魚綱スズキ目アジ科に属する海水魚。本州中部以南の太平洋およびハワイ、サモア、インド洋にかけて広く分布し、沿岸にすむ。南日本各地では定置網や釣りで漁獲される。全長90センチメートルに達し、体は菱(ひし)形に近く、大きく側扁(そくへん)している。幼期では第2背びれと臀(しり)びれの前部の軟条は糸状に伸び、長さは全長の2倍余りになるが成長とともに短くなる。稜鱗(りょうりん)（ぜんご）は小さく尾柄(びへい)部付近の側線の直走部にだけある。食用魚としての価値は低いが、幼魚はひれをなびかせて泳ぐ姿が優美なので、水族館などでの観賞用として人気がある。

［鈴木　清］

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