World first! Longest-Ever Rearing of Double-lined fusilier Larvae and Juveniles!! A Species Native to Okinawa Prefecture

At Okinawa Churaumi Aquarium, we have achieved the world’s first successful long-term rearing of double-lined fusilier larvae and juveniles, a species of fish native to Okinawa Prefecture. An exhibit of the larvae and juveniles has begun.

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  Double-lined fusilier    Four days after hatching

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  Double-lined fusilier  Three months after hatching

Place of exhibit

Double-lined fusilier  Three months after hatching

Size of Exhibit

Three individuals (Total length 5 cm)
*Exhibit may close depending on the condition of the animals.

We have been working for many years on breeding double-line fusiliers. We have published our research on spawning behavior and egg development. However, the eggs from this type of fish are very small (0.8 mm in diameter), as are their hatched larvae. They are extremely difficult to rear when young. However, by improving early-stage diets and rearing methods, we achieved the world’s first long-term rearing of the double-lined fusilier, successfully rearing them to the juvenile stage.

The exhibit features individuals that hatched in the “backyard” rearing area in June 2026. They were around 3.1 mm in length at hatching. After about 3 months, they had reached 50.5 mm in length. They had also developed the same longitudinal lines as the adult, and black tips on the caudal fins as seen in double-lined fusiliers.

Adult double-lined fusiliers

＜Double-lined fusilier＞
学名：Pterocaesio digramma
英名：Double-lined fusilier

The double-lined fusilier is Okinawa's official prefectural fish, it is known as gurukun in the Okinawan language. In Japan, it inhabits coral reef areas south of Amami Oshima Island. It reaches 30 cm in length. They form large schools, and are a popular catch for anglers. It is a well-loved dish in traditional Okinawan cooking.

At Okinawa Churaumi Aquarium, we will continue to shed light on the reproduction and life cycle of the double-lined fusilier. We aim to build our knowledge of its breeding and rearing while advancing research that supports the conservation and sustainable use of this important fisheries resource in Okinawa Prefecture.