The mandarinfish is a small, brightly colored member of the dragonet family, which is popular in the saltwater aquarium trade. The mandarinfish is native to the Pacific, ranging approximately from the Ryukyu Islands south to Australia. To date, S. splendidus is one of only two vertebrate species known to have blue colouring because of cellular pigment. Mandarinfish are reef dwellers, preferring sheltered lagoons and inshore reefs. While they are slow-moving and fairly common within their range,
they are not easily seen due to their bottom-feeding habit and their
small size (reaching only about 6 cm). They feed primarily on small crustaceans and other invertebrates.
This is the other species of vertebrate with blue cellular pigment, the Picturesque Dragonet! (They’re very closely related to Mandarinfish). If you want to know more about why any animal not one of these fish only appears to be blue, here’s a great article!
Plume de Lynx 
