Group

Dragonfish

Stomiiformes

marine

About Dragonfish

Stomiiformes is an order of deep-sea ray-finned fishes of very diverse morphology. It includes, for example, dragonfishes, lightfishes (Gonostomatidae and Phosichthyidae), loosejaws, marine hatchetfishes and viperfishes. The order contains 4 families (5 according to some authors) with more than 50 genera and at least 410 species. As usual for deep-sea fishes, there are few common names for species of the order, but the Stomiiformes as a whole are often called dragonfishes and allies or simply stomiiforms.

The scientific name means "Stomias-shaped", from Stomias (the type genus) + the standard fish order suffix "-formes". It ultimately derives from Ancient Greek stóma (στόμᾶ, "mouth") + Latin forma ("external form"), the former in reference to the huge mouth opening of these fishes.

The earliest stomiiform is Paravinciguerria from the Cenomanian of Morocco and Italy.

Appearance

Members of this order are mostly pelagic fishes living in deep oceanic waters. Their distribution around the world's oceans is very wide, ranging from subtropical and temperate waters up to subarctic or even Antarctic ones.

The smallest species of this order is the bristlemouth Cyclothone pygmaea. Native to the Mediterranean Sea, it reaches just 1.5 cm (0.6 in) as an adult. The largest species is the barbeled dragonfish Opostomias micripnus, widely found in the Atlantic, Indian and Pacific Oceans and measuring about 50 cm (20 in) in adult length.

Reproduction

Stomiiforms spawn generally in deep seas, but the eggs are light and float towards the ocean surface. They hatch in surface waters. When the larvae have completed their metamorphosis and look like adults, they descend to join the main population.

Like many benthic fish species, certain members of the order – especially in the genera Cyclothone and Gonostoma – change their sex during their life. When they become sexually mature, they are males; later on they transform into females.

Where to see it

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