Indian mackerel

Widely distributed along the coasts of the tropical and subtropical Indo-Pacific. In Japan, it is only found in Okinawa. Its Japanese name is also the local Okinawan name gurukuma. It reaches 40 cm in length. This fish has gill rakers in its gills that act as a comb to filter plankton. They swim and feed with their mouth open wide, which makes them look like Japanese carp streamers (koinobori). This behavior is seen in the aquarium during feeding or right after other fish have spawned. This fish is commonly eaten in Okinawa.