The dragonet – Callionymidae – is a family of small, bright-colored and slow-moving fish that includes 139 species. Dwelling mostly the bottom of the warm and shallow waters of the Indo-Pacific, as well as the Mediterranean and Eastern Atlantic, dragonets are calm and hardy little creatures distinguished by their colorful patterns, their large, spiny fins and their big mouths and eyes.
All dragonets have elongated scaleless bodies that are very conspicuous due to their bright coloring and very large dorsal fins, which distinguish them from other species similar in terms of appearance, such as gobies. The almost 140 different species that belong to the genera differ considerably in terms of size – the smallest species, the Saint Helena, measures only 2 cm, while the largest species, named after its long tail can reach 30 cm. They spend much time buried in the sand of the sea bed, that is why their gills are located relatively high on their heads. Dragonets are sexually dimorphic, the males being much larger than the females and having much larger fins as well. Other common physical features of the dragonet (Callionymidae) include the large preopercular spine, which is venomous in some species. The first of the high dorsal fins comprises four spines that get further extensions in males.
Dragonets feed all the time. Their preferred sources of nutrients include the tiny invertebrates – such as copepods, mollusks, shell fish and amphipods – that they find through and around seagrass. They are not territorial or choosy when it comes to food – they will feed on any small crustaceans they can find in their habitat and they are also able to alter their dietary preferences if the composition of the available crustaceans changes or they move to a different habitat. While feeding, dragonets grab their food with the help of their protractible jaws – they extend the jaw and direct the victim towards the mouth.
Dragonets reproduce by spawning, usually not long before sunset. The mating starts with courtship signaled by both the male and the female by spreading their fins and swimming around the partner, followed by pairing, ascending to maximum 1.2 meters from the sandy bottom. Then comes the the release of the eggs, which float freely for a while. The males are polygynous, so after mating, the male dragonet (Callionymidae) moves on immediately, looking for another lady to charm.