: Chauliodus sloani
Sub Phylum Vertebrate
Viperfish are found in tropical and temperate waters throughout the world at depths of up to 9,00 feet (2,800 meters). They are rarely seen by humans, although specimens do sometimes show up in the catches of deep water trawlers The Viper fish is one of the fiercest predators of the deep.
The viperfish is one of the most unusual-looking fish in the deep sea. It has a black, elongated body, a large mouth and very long, transparent fangs.. The sharp, fang-like teeth, do not fit inside its mouth, but curve back very close to the eyes. The unusually large teeth of the viperfish help it to grab hold of its prey at it hunts in the darkness. The fish may use these teeth to impale its victims by swimming at them at high speeds.
The first vertebra, right behind the head, acts as a shock absorber. This fish has a long dorsal spine tipped with a photophore, a light-producing organ, which it flashes on and off to attract smaller fish. It may hang motionless in the water, waving its lure over its head. The hinged skull can be rotated up to swallow large prey, while the large stomach can stock up on food when it is plentiful. In spite of its ferocious appearance, the viperfish is a relatively small animal, growing to about 30 centimeters in length. It is usually dark silvery blue in color, but its coloration can vary from green to silver or black.
The photophores along the sides of the body may be used to attract prey and communicate with potential mates or rivals. Viperfish have a very low basal metabolic rate, which means they can go for days without food. This adaptation is likely a result of the scarce nature of food in the deep sea. Viperfish are known to be preyed upon by sharks and some species of dolphin.
Because of the extreme depths at which they are found, very little is known about the reproductive habits of the viperfish. It is believed that they are external spawners, meaning that the female releases eggs into the water to be fertilized. Spawning probably occurs throughout the year, although the numbers of young larvae have been discovered to be highest between January and March. These larvae are approximately six millimeters long (approximately a quarter of an inch) when they hatch. They are left to fend for themselves until they can reach maturity. Not much is known about the life span of the viperfish, but most researchers think they live between 15 and 30 years.