View source for Pearleye

{{Short description|Family of ray-finned fishes}}
{{automatic taxobox
| name = Pearleyes
| image = Benthalbella infans.JPG
| image_caption = ''Benthalbella infans''
| taxon = Scopelarchidae
| authority = Alcock, 1896
| subdivision_ranks = [[Genus|Genera]]
| subdivision = ''[[Benthalbella]]''<br/>
''[[Lagiacrusichthys]]'' <ref name=Davis2015>{{cite journal|doi=10.1643/ci-14-139|title=Evolutionary Relationships of the Deep-Sea Pearleyes (Aulopiformes: Scopelarchidae) and a New Genus of Pearleye from Antarctic Waters |year=2015 |last1=Davis |first1=Matthew P. |journal=Copeia |volume=103 |issue=1 |pages=64–71 |s2cid=86731010 |doi-access=free }}</ref><br/>
''[[Rosenblattichthys]]''<br/>
''[[Scopelarchoides]]''<br/>
''[[Scopelarchus]]''
}}
The '''pearleyes''' are a [[family (biology)|family]], '''Scopelarchidae''', of [[Aulopiformes|aulopiform]] [[ray-finned fish]], distinguished by their unique visual system, with two [[retina]]s in each eye.<ref name=EoF>{{cite book |editor=Paxton, J.R. |editor2=Eschmeyer, W.N.|author1=Johnson, R.K.  |author2=Eschmeyer, W.N. |name-list-style=amp |year=1998|title=Encyclopedia of Fishes|publisher= Academic Press|location=San Diego|page= 126|isbn= 0-12-547665-5}}</ref>
They are small to medium fish, ranging in size from just {{convert|3.7|cm|in|abbr=on}} in adult length to {{convert|35|cm|in|abbr=on}} in length, depending on species. They have a similar appearance to [[lizardfish]]es, with a large mouth, numerous teeth, and a forked tail. The [[dorsal fin]] is located in the middle of the back, with a small [[adipose fin]].<ref name=EoF/>
Like many other deep-sea fish, their eyes are telescopic, allowing them to see in near darkness. However, unlike any other fishes, their eyes also possess a "pearl organ"; a white spot on the surface of the eye that may help to pick up light from the side of the fish, out of the normal visual field. The pearl organ is associated with a secondary retina, allowing the fish an unusually wide field of view.<ref name=EoF/> Specifically, pearleyes can see up to 20 degrees below the horizontal despite the nearly 40-degree angle created by the tubular eyes of the pearleye above the horizontal.<ref>{{cite journal| title = On the lens pad of ''Benthalbella infans'', a scopelarchid deep-sea teleost| year = 2000| last = Locket| first = N. A.| journal = Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences| volume = 355| issue = 1401| pages = 1167–1169| pmid = 11079391| pmc = 1692853| jstor = 3066638| doi = 10.1098/rstb.2000.0660}}</ref> While the majority of pearleye species are found in tropical waters, pearleyes have been found in every ocean in the world, including the ''Lagiacrusichthys,'' a newly described genus found in the Antarctic Ocean.<ref>Davis, M. P., (2015). Evolutionary Relationships of Deep-Sea Pearleyes (Aulopiformes: Scopelarchidae) and a New Genus of Pearleye from Antarctic Waters. ''Copeia'', 103(1), pp 64–71. doi.org/10.1643/CI-14-139</ref>
Pearleyes typically live between {{convert|500|and|1000|m|ft|abbr=on}}, although some species may visit shallower waters during the night.<ref name=EoF/>
==References==
{{Reflist}}
{{Taxonbar|from=Q1501875}}
[[Category:Scopelarchidae| ]]