{{short description|Species of fish}} {{other uses}} {{Use dmy dates|date=May 2022}} {{Speciesbox | image = Lookdown25.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 20 November 2021">{{cite iucn |author=Smith-Vaniz, W.F. |author2=Williams, J.T. |author3=Pina Amargos, F. |author4=Curtis, M. |author5=Brown, J. |date=2015 |title=''Selene vomer'' |volume=2015 |article-number=e.T16507307A16510397 |doi=10.2305/IUCN.UK.2015-4.RLTS.T16507307A16510397.en}}</ref> | taxon = Selene vomer | authority = (Linnaeus, 1758) | synonyms = {{hidden begin|title = List}} *''Zeus vomer'' <small>Linnaeus, 1758</small> *''Zeus gallus'' <small>Linnaeus, 1758</small> *''Zeus kleinii'' <small>Walbaum 1792</small> *''Selene argentea'' <small>Lacépède, 1802</small> *''Zeus capillaris'' <small>Mitchill, 1815</small> *''Zeus rostratus'' <small>Mitchill, 1815</small> *''Zeus geometricus'' <small>Mitchill, 1818</small> *''Argyriosus mauriceii'' <small>Swainson, 1839</small> *''Argyriosus setifer'' <small>Swainson, 1839</small> *''Platysomus (Argyriosus) riacanthus'' <small>Swainson, 1839</small> *''Zeus columba'' <small>Larrañaga, 1923</small> *''Zeus rhomboides'' <small>Larrañaga, 1923</small> {{hidden end}} | synonyms_ref = <ref name = CofF>{{Cof genus|genus=''Selene''|access-date=4 December 2019}}</ref> }}
The '''lookdown''' ('''''Selene vomer''''') is a species of game fish in the family Carangidae. It was first described in 1758 by Carl Linnaeus, in the 10th edition of ''Systema Naturae''.
==Description== Although the lookdown is similar to the Atlantic moonfish, it can be distinguished by its dorsal and anal fins, the second ray on each fin being many times longer than the surrounding rays. This gives the dorsal and anal fins a noticeably scythe-like shape.<ref name="gma.org">{{cite web |url=http://www.gma.org/fogm/Selene_vomer.htm |title=Selene vomer|work=gma.org |access-date=2008-05-01 }}</ref> The dorsal fin of the lookdown has 9 spines and 23 rays, while the anal fin has only 3 spines and 18 rays.<ref name=fishbase>{{cite web |url=http://www.fishbase.org/Summary/SpeciesSummary.php?id=1004 |title= ''Selene vomer'' (Linnaeus, 1758)|work=Fishbase |access-date=2008-05-02 }}</ref>
Like the Atlantic moonfish, it has a deep, rhombus-shaped, laterally-compressed body.<ref name="gma.org"/> The head has the mouth set low and the eyes high. The overall profile of the head is concave.<ref name="gma.org"/> The caudal fin is forked, as in the pompanos, while the pectoral fin is scythe-like and reaches the middle of the second dorsal fin.<ref name="gma.org"/>
The lookdown is silvery on both sides with a darker tinge on top. A young fish has several faint vertical bars that fade as it grows.<ref name="gma.org"/> The longest lookdown known was {{Convert|48.3|cm||abbr=on}} long,<ref name="Cervigón, F. 1993">Cervigón, F. (1993). ''Los peces marinos de Venezuela''. Volume 2. Fundación Científica Los Roques, Caracas, Venezuela.</ref> and the heaviest weighed {{Convert|2.1|kg|}}.<ref>IGFA (2001). Database of IGFA angling records until 2001. IGFA, Fort Lauderdale, USA.</ref>
==Distribution and habitat== In the western Atlantic, the lookdown is found from Canada<ref>Scott, W.B. and M.G. Scott (1988). ''Atlantic fishes of Canada''. Can. Bull. Fish. Aquat. Sci. 219.</ref> and Maine south to Uruguay,<ref name="Smith, C.L. 1997">Smith, C.L. (1997). ''National Audubon Society field guide to tropical marine fishes of the Caribbean, the Gulf of Mexico, Florida, the Bahamas, and Bermuda''. Alfred A. Knopf, Inc., New York.</ref> including Bermuda and the Gulf of Mexico.<ref name="Cervigón, F. 1993"/> Although it is common in tropical Atlantic waters, it is rarely seen in the Greater Antilles.<ref name="Smith, C.L. 1997"/>
The lookdown is found in marine and brackish waters at depths of {{Convert|1 to 53|m|ft|sp=us|sigfig=2}}.<ref name="gma.org"/> It lives in shallow water near the coast, along hard or sandy bottoms.<ref name=fishbase/> Juveniles may be seen in estuaries<ref name="Cervigón, F. 1993"/> or near sandy beaches.<ref>Cervigón, F., R. Cipriani, W. Fischer, L. Garibaldi, M. Hendrickx, A.J. Lemus, R. Márquez, J.M. Poutiers, G. Robaina and B. Rodriguez (1992). Fichas FAO de identificación de especies para los fines de la pesca. Guía de campo de las especies comerciales marinas y de aquas salobres de la costa septentrional de Sur América. FAO, Rome.</ref> The lookdown often shoals, but it may also break away into smaller groups or pairs.<ref>Coupal, L., E. Bédard, C. Peguero and I.S. Durante (1992). ''Repertorio ictionímici de la República Dominicana''. Fáscículo I : Acanthuridae – Carangidae. LIRD.</ref>
==Commercial importance== The lookdown does not play a significant role in commercial fisheries. However, it is sought after for large public aquarium displays due to its interesting shape and flashy appearance.{{Citation needed|date=July 2022}}
==Gallery== <gallery mode="packed"> File:Lookdown at MBA.webm File:Selene vomer SI.jpg File:Selene vomer X-ray.jpg|X-ray image File:Selene vomer 01.jpg File:Selene vomer 02.jpg File:Selene vomer Nice 226 Lookdown C.jpg File:Fish4445 - Flickr - NOAA Photo Library.jpg|A naturally occurring Lookdown, in the Gulf of Mexico </gallery>
==References== {{Commons category|Selene vomer}} {{Wikispecies|Selene vomer}} {{Reflist}}
==External links== * {{sealifephotos|159649}}
{{Taxonbar|from=Q889541}}
Category:Selene (fish) Category:Fish of the Eastern United States Category:Fish of the Western Atlantic Category:Fish described in 1758 Category:Animal taxa named by Carl Linnaeus