''Histioteuthis'' is a genus of

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

in the family

Histioteuthidae Histioteuthidae is a family of Oegopsid squid. The family was previously considered to be monotypic but the World Register of Marine Species assigns two genera to this family. The species classified under Histioteuthidae are mostly weakly musc ...

. It goes by the

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of the right eye, tubular, yellow-green, faces upward, and bulges out of the head. In 2017, researchers at

Duke University Duke University is a private research university in Durham, North Carolina. Founded by Methodists and Quakers in the present-day city of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco and electric power industrialist James ...

established that ''Histioteuthis'' uses its larger eye to see ambient

sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...

, and its smaller eye to detect

bioluminescence Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some b ...

from prey animals.Mismatched Eyes Help Squid Survive Ocean’s Twilight Zone
at

; by Kara Manke; published February 13, 2017; retrieved June 25, 2017 The name is composed of the Greek ' (, "sail", a large webbed membrane between six of the arms, in some species) and ' ("squid"). The genus contains bioluminescent species.

Species

*''H. bonnellii'' species-group **''

Histioteuthis bonnellii ''Histioteuthis bonnellii'', the umbrella squid, is a species of cock-eyed squid belonging to the family Histioteuthidae. Distribution This species is distributed mostly in the Atlantic Ocean. It can be found off the coast of Argentina, South Af ...

'', umbrella squid **''

Histioteuthis machrohista ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' *''H. reversa'' species-group **''

Histioteuthis eltaninae ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter ...

'' **''

Histioteuthis atlantica ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter ...

'' **''

Histioteuthis reversa ''Histioteuthis reversa'', commonly known as the reverse jewel squid or the elongate jewel squid, is a species of cock-eyed squid, so called because the eyes are dissimilar. It occurs at moderate depths in the Atlantic Ocean and Mediterranean Se ...

'', reverse jewel squid *''H. celetaria'' subspecies-group **''

Histioteuthis celetaria celetaria ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' **''

Histioteuthis celetaria pacifica ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' *''H. corona'' subspecies-group **''

Histioteuthis corona berryi ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' **''

Histioteuthis corona cerasina ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' **''

Histioteuthis corona corona ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' **''

Histioteuthis corona inermis ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of ...

'' *''H. miranda'' species-group **''

Histioteuthis miranda ''Histioteuthis'' is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter ...

'' **'' Histioteuthis oceani'' *''H. meleagroteuthis'' species-group **''

Histioteuthis heteropsis ''Histioteuthis heteropsis'' (''H. heteropsis''), also known as the strawberry squid, is a species of small cock-eyed squid. The scientific nomenclature of these squid stems from their set of differently sized eyes, one being small and blue and ...

'', strawberry squid **'' Histioteuthis meleagroteuthis''

References

External links

Histioteuthidae discussion forum at TONMO.com
Squid Bioluminescent molluscs {{squid-stub