Sloane's viperfish

Sloane's viperfish, Chauliodus sloani, is a predatory mesopelagic dragonfish found in waters across the world.

[3] The species was first described by German scientists Marcus Elieser Bloch and Johann Gottlob Schneider in their 1801 book Systema ichthyologiae: iconibus CX illustratum, volume 1.

[6] It is believed that C. sloani can adjust the intensity of bioluminescence of the ventral photophores to camouflage itself from predators that might see its shadow from below.

Viperfishes are deep-sea fishes with photophores (light-producing organs), long teeth, and hinged jaws.

[9] In the central Mediterranean Sea, C. sloani is eaten as a primary part of the diet of the Atlantic bluefin tuna.

The size, shape, location, and number of teeth are consistent across individuals of C. sloani, and each fang is highly specialized.

Recent research suggests that it improves the mechanical advantage of the system by anteriorly displacing the intersegmental aponeurosis during adduction, which increases bite force and angular velocity.

Like many stomiiformes, its scales and caudal skeleton are poorly ossified and it lacks a gas-filled swim bladder.

[9][18] An average C. sloani individual probably consumes at least one lanternfish every twelve days[9] and there is no evidence to suggest that they increase their intake of food the bigger they are.

[20] The fish is considered a specialist predator given the small list of prey that were observed in the stomach content analysis.