They are commonly referred to as pygmy angelfishes, due to their generally much smaller size than other angelfish genera. The species are variably distributed in tropical and subtropical seas of the world. Few have large geographical distributions and some are endemic to tiny oceanic outposts, an island , or small island group. They occur on algal-rocky and coral reefs, and most species live in shallow waters at depths to about 15m, but some range to 70m or more, and a few inhabit only depths of more than 50m. Pygmy angelfishes are quick-darting and often shy species that hug the substrates with tunnels and crevices, ready to disappear and appear again several metres away.
Place of origin:Western Pacific
Northern Pacific, ranging from southern Japan to Midway and the Hawaiian Islands. Inhabits rocky reefs and coral reefs to depths of about 60m, usually deeper than 15m. This species usually forms a harem, comprising the dominant male with several females or subadults. Variable in colouration but basic colours bluish purple with orange or yellow. Males have an almost blue head, with spots around eye, which is yellowish in females. Some individuals in Midway population are more yellowish. In Hachijoh-jima yellow forms can be seen only in a deeper water, while normal ones occur in shallower water. They are often observed taking faeces released from other fishes there. Perhaps the largest species in the genus, reaching up to 19cm.