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155. Slow Dragonet (Callionymus aagilis)


The Slow Dragonet (Callionymus aagilis) is a small and elusive fish species that has only been seen a few times in the waters of Réunion and Mauritius in the Indian Ocean. It is possible that it also inhabit the island of Rodrigues, which is an other islands of the Mascareignes, a group of tropical islands in the southwestern Indian Ocean, situated between 700 and 1500 kilometres east of Madagascar.

The Slow Dragonet belongs to the family of dragonets, which are a group of small, sometimes vibrantly coloured bottom-dwelling marine fishes found in shallow waters of tropical and subtropical regions of the Atlantic, Indian, and Pacific Oceans. Dragonets belong to the family Callionymidae (from the Greek kallis, "beautiful" and onyma, "name"). These bottom dwelling small fish are characterised by their elongated bodies, large heads, and spiny fins. There are 139 species, belonging to nineteen genera.

This species is extremely rare, and before 2013, it had never been observed in its natural habitat. It was discovered by a team of researchers from the University of Reunion Island who were conducting a survey of the shallow waters around the island. Since then, only a handful of individuals have been observed, making it one of the rarest marine fish species in the world.

We are delighted to have spotted and filmed one of these rare fish on one of our dives. Unfortunately we didn’t know it was so rare, otherwise we would have collected more underwater video footage of this little fish. It was only when examining the footage after the dive, that we discovered we that had struck gold, by filming this extremely rare fish. The number of encounters of this endemic species in its natural habitat are fewer than ten. If only we would have known this, we probably would have stayed with this individual the entire dive and filmed and documented all of its moves.

The Slow Dragonet is a sand-dwelling species, and it spends most of its time on the sandy substrate, sometimes partially buried where it is well-camouflaged and difficult to spot. It is typically found in shallow waters, at depths ranging from 2 to 10 meters, where it feeds probably on small crustaceans and other invertebrates that live in the sand.

One of the most distinctive features of the Slow Dragonet is the white spots on its flanks, which are thought to help break up its outline and make it less visible to predators. The honeycomb pattern on its cheeks and snout is another characteristic feature that helps to distinguish it from other dragonet species.

Because of its rarity, very little is known about the biology and ecology of the Slow Dragonet. It is believed to have a relatively small range and its population size is likely to be very small. This makes it highly vulnerable to a range of threats, including habitat loss and degradation, overfishing, and pollution.


With the fish being almost invisible against its background this image had its share of challenges. Therefore I opted to make the image crispier by increasing the contrast a bit. A subtle vignette draws the eye to the center where the animal is.

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