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Sloane's Viperfish

Chauliodus sloani


The genus name of this fish comes from the Greek words chaulios, meaning "to be with mouth opened," and odous, meaning "teeth." The name is appropriate, as Sloane's viperfish has the largest teeth to head size; those teeth are over half the size of the head, and overlap the jaws when the mouth is closed.

close-up of Sloane's Viperfish

Sloane's viperfish reaches a maximum length of 14 inches. It has an adipose fin and a forked caudal fin and its dorsal fin is positioned right behind the head. Almost all of the fins contain soft rays. The first soft ray of the dorsal fin is elongated and extends to about half the length of the body. There are rows of 24 or more light-producing cells along the lateral and ventral surface of the fish. General body color is blue, green, black, or silver.

Sloane's Viperfish

Distribution and Habitat

Sloane's viperfish inhabits almost all marine waters in temperate and tropical zones, including the western Mediterranean, South China, and East China seas, but with several distributional gaps in the southern central Atlantic, northern Indian Ocean, eastern Pacific north of the equator, etc. Specimens have been found from as deep as 9,186 feet, up to 1,312 feet. It is believed that it migrates vertically at night in search of food.


Like many deep-water fishes, Sloane's viperfish has a straight intestine and an elongated, distensible stomach, as well as a relatively large gape and hinged fangs. These features allow it to prey on fish up to 63% of its own body length. It is presumed that it waits at depths that act as common passages for other vertical migrators and catches prey as they ascend to feed, using its elongated first dorsal ray as a lure. Its specialized dentition can rotate inward to prevent prey from escaping and ease its passage into the gullet. A unique feature is a hinged connection between the skull and backbone that rotates the skull upward to allow further manipulation of large prey into the throat.


Very little is known about this fish's mating behavior, but it can be presumed that its light-producing cells may play a role in mate attraction. Spawning probably occurs year round, but larvae are known to be in the highest numbers from January to March. The less-than-half-inch-long larvae are similar to those of eels in appearance. It is not known how long it takes to grow from the larval stage to the adult form, nor has a maximum lifespan in the wild been determined.

Scientific Classification

phylum Chordata
subphylum Vertebrata
superclass Osteichthyes
class Actinopterygii
order Stomiiformes
family Stomiidae
genus & species Chauliodus sloani


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The Robinson Library >> Class Actinopterygii

This page was last updated on September 28, 2018.