The mandarin fish is a brightly colored member of the dragonet family. They are found in the tropical waters of the southwestern Pacific Ocean down to 60 ft (18 m) deep.
Their vibrant colors signal to other animals that they are dangerous to consume. Since these fish have no scales, their body produces a toxic mucus coating that emits an unpleasant smell. Along with deterring predators, the mucus also protects them from parasites.
Each mandarin fish has its own unique color pattern. In order to achieve their bright coloration, they produce blue pigmented, light reflective cells called cyanophores.
Mandarinfish only reaches about 3 inches (8 cm) long. Males are slightly larger than females and they can be very territorial. Males also have a longer spined dorsal fin.
Mandarinfish are normally found in small groups among coral or swallow protected lagoons. They typically feed on small bottom-dwelling invertebrates. Because of their vibrant colors, mandarin fish are commonly collected for the aquarium trade. However, they are very difficult to keep in captivity due to their specific feeding habits.