Okinawa Pygmy Goby

Trimma okinawae

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Gobiiformes
Family: Gobiidae
Genus: Trimma
Species: Trimma okinawae

The Okinawa pygmy goby (Trimma okinawae) is a tiny orange-red goby with yellow spots, famous for being able to change sex in both directions. Its translucent body glows in a torch beam.

It grows to about 3 cm and lives in small groups in caves and crevices on the reef. The largest fish in a group is usually male, and if a bigger male appears it can switch back to female, a rare ability among vertebrates.

The Okinawa pygmy goby occurs in the western Pacific, including the Philippines, where it lives in shaded holes and overhangs on reef slopes.