The Red-Tailed Halfbar Wrasse World’s First Exhibit of the Red-and-White Deep-Sea Wrasse Collected off the Coast of Kume Island!

At Okinawa Churaumi Aquarium, we are now exhibiting the world’s first live display of the red-tailed halfbar wrasse.

 

Scientific name：Decodon erythroleukos

This deep-sea wrasse was described as a new species in 2025. It has been 50 years since a new species was described in the genus Decodon. This is just the second Decodon species found in Japanese waters. Its scientific name “erythroleukos” is Greek for red and white, and derives from the wrasse’s red-and-white caudal fin. This red-and-white caudal fin is the main feature that distinguishes it from other closely related species.

The red-tailed halfbar wrasse on display was collected at a depth of 130 meters off the coast of Kume Island in July 2026. Only three individual specimens are known worldwide, and few underwater images exist. This is truly a rare sight. This is the only individual ever reared and exhibited in the world.

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  A remotely operated vehicle image taken at a depth of 200 meters offshore of Ie Island in May 2025

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  Underwater drone images taken at a depth of 150 meters off the coast of Ishigaki Island in March 2026.

Past surveys conducted by our facility using an ROV (remotely operated vehicle) and an underwater drone captured images of this species inhabiting rocky reefs on the seafloor.
We have replicated this environment in our tank. You can spot the red-tailed halfbar wrasse hiding amongst the rocks.

At Okinawa Churaumi Aquarium, we will continue our research by rearing and exhibiting this species and other marine organisms to better understand their ecology.
 

Place of exhibit

Small Life in the Deep Sea in the Okinawa Churaumi Aquarium

Size of Exhibit

Decodon erythroleukos One individual
*Exhibit may close depending on the condition of the animals.