Histioteuthis

{{short description|Genus of cephalopods known as cock-eyed squids}}

{{Automatic taxobox

| image = Histioteuthis NOAA.jpg

| image_caption = A member of the genus Histioteuthis. Eye asymmetry is observable.

| taxon = Histioteuthis

| authority = Orbigny, 1841{{cite web | url = http://www.marinespecies.org/aphia.php?p=taxdetails&id=138074 | title = Histioteuthis d'Orbigny [in Férussac & d'Orbigny], 1841 | accessdate = 6 March 2018 | publisher = Flanders Marine Institute | author = Julian Finn | year = 2016 | work = World Register of Marine Species}}

| type_species = Cranchia bonnellii

| type_species_authority = Férussac, 1834

| subdivision_ranks = Species

| subdivision = 17 species and subspecies, see text

| synonyms = *Calliteuthis Verrill, 1880

• Histiopsis Hoyle, 1885
• Histiothauma Robson, 1948
• Hoylia Cossmann, 1900
• Lolidona Risso, 1854
• Meleagroteuthis Pfeffer, 1900

| synonyms_ref =

}}

File:Histioteuthis bonellii beak.jpg]]

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 the right eye, tubular, yellow-green, faces upward, and bulges out of the head.

In 2017, researchers at Duke University established that Histioteuthis uses its larger eye to see ambient sunlight, and its smaller eye to detect bioluminescence from prey animals.[https://today.duke.edu/2017/02/mismatched-eyes-help-squid-survive-ocean%E2%80%99s-twilight-zone Mismatched Eyes Help Squid Survive Ocean’s Twilight Zone], at Duke University; by Kara Manke; published February 13, 2017; retrieved June 25, 2017

The name is composed of the Greek {{Transliteration|grc|histion}} ({{lang|grc|ἱστίον}}, "sail", a large webbed membrane between six of the arms, in some species) and {{Transliteration|grc|teuthis}} ("squid").{{cite book|last=Catlow|first=Agnes|authorlink=Agnes Catlow|title=Popular Conchology|url=https://archive.org/details/popularconcholog00catl_1|year=1854|publisher=Longman|page=[https://archive.org/details/popularconcholog00catl_1/page/364 364]|quote= Histioteuthis, sail, and cuttlefish}}{{cite book|last=Chun|first=Carl|authorlink=Carl Chun |title=The Cephalopoda|url=https://books.google.com/books?id=39cNAQAAIAAJ|year=1975|publisher=Israel Program for Scientific Translations|isbn=978-0-7065-1259-5|page=120|quote= Histioteuthis is characterized by such a large membrane ("sail") [...] This "sail" is a strong, muscular cutaneous membrane which surrounds the 1st, 2nd and 3rd arms}}

The genus contains bioluminescent species.{{cite journal |last1=Herring |first1=Peter J. |title=Systematic distribution of bioluminescence in living organisms |journal=Journal of Bioluminescence and Chemiluminescence |date=1987 |issue=3|volume=1 |pages=147–163|doi=10.1002/bio.1170010303 |pmid=3503524 }}