What Divers Should Know About Dragonet

Dragonets, belonging to the diverse Callionymidae family, are primarily encountered in the tropical waters of the western Indo-Pacific. These small percomorph marine fish are benthic organisms, often spending their time near sandy bottoms. Many species inhabit depths of roughly two hundred meters. The group comprises 139 species across nineteen genera.

Often mistaken for gobies, dragonets exhibit distinct characteristics: males possess very long dorsal fins; females display protruding lower jaws. These 'little dragons' are generally very colorful, adorned with cryptic patterns. Their elongated, scaleless bodies feature a large preopercular spine, reported as venomous in some species. All fins are characteristically large and showy, with males often displaying filamentous extensions on their high dorsal fins.

Size varies significantly, from the largest longtail dragonet reaching 30 centimetres (12 inches) to the tiny Saint Helena dragonet at just 2 centimetres. Marked sexual dimorphism is common, with males typically more brightly coloured, differently patterned, and possessing much higher dorsal fins than females.