It is believed the bright coloration of the mandarinfish both attracts mates and warns would-be predators of their toxic nature.
Coloration is primarily blue with orange, yellow, and red wavy lines
Body is covered in thick mucus instead of scales
Head is broad and depressed
Instead of scales, mandarinfish are covered in a thick mucus that is both bitter in both taste and smell. They also have a layer of cells that release substances with some toxins.
While adult mandarinfish are commonly found feeding upon live rock in reefs, their eggs are pelagic, floating within the water column. Development occurs quickly with juvenile mandarinfish settling on the reef bottom, resembling miniature adults with 12 to 14 days after fertilization. Adult mandarinfish have no involvement in caring for their eggs past fertilization.
The International Union for Conservation of Nature (IUCN) has listed the mandarinfish population as Least Concern due to the lack of exploitation across the entirety of its range. Least Concern populations are those that are unlikely to become extinct in the near future
0.01 to 2.5 inches (0.02 to 6 centimeters)
Marine worms, protozoans, and small crustaceans
Western Pacific Ocean, including Philippines, Indonesia, Australia, and New Guinea