{{Short description|Seabream endemic to South Africa}} {{Speciesbox | image = Janbruin at Whittle Rock DSC09125.JPG | image_alt = | image_caption = Janbruin at [[Whittle Rock]] | status = LC | status_system = IUCN3.1 | status_ref = <ref name = iucn>{{cite iucn |author=Mann, B.Q. |author2=Buxton, C.D. |author3=Russell, B. |author4=Pollard, D. |author5=Carpenter, K.E. |author5-link=Kent E. Carpenter |name-list-style=& |year=2014 |title=''Gymnocrotaphus curvidens'' |article-number=e.T170193A1290621 |doi=10.2305/IUCN.UK.2014-3.RLTS.T170193A1290621.en |access-date=28 January 2024}}</ref> | parent_authority = Günther, 1859 | taxon = Gymnocrotaphus curvidens | authority = [[Albert Günther|Günther]], 1859 }}
'''''Gymnocrotaphus''''' is a ''monospecific genus'' of marine [[Actinopterygii|ray-finned fish]] belonging to the [[Family (taxonomy)|family]] [[Sparidae]], which includes the seabreams and porgies. The only species in the genus is the '''''Gymnocrotophus curvidens''''', the '''Janbruin''', an [[Endemism|endemic]] to the coasts of South Africa.
==Taxonomy== ''Gymnocrotaphus'' was first proposed as a monospecific genus in 1859 by the German-bprn British [[herpetologist]] and [[ichthyologist]] [[Albert Günther]]<ref name = CofF>{{Cof family|family=Sparidae|access-date=28 January 2024}}</ref> when he [[Species description|described]] its only species, ''Gymnocrotaphus curvidens'', from the [[Cape of Good Hope]].<ref name = CofF2>{{Cof genus|genus=Gymnocrotaphus|access-date=28 January 2024}}</ref> This taxon is placed in the family Sparidae within the [[Order (biology)|order]] [[Spariformes]] by the 5th edition of ''[[Fishes of the World]]''.<ref name = Nelson5>{{cite book |author1=Nelson, J.S. |author1-link=Joseph S. Nelson |author2=Grande, T.C. |author3=Wilson, M.V.H. |year=2016 |title=Fishes of the World |edition=5th |publisher=[[John Wiley & Sons]] |place=Hoboken, NJ |pages=502–506 |isbn=978-1-118-34233-6 |lccn=2015037522 |oclc=951899884 |ol=25909650M |doi=10.1002/9781119174844}}</ref> Some authorities classify this genus in the subfamily Boopsinae,<ref name = Parenti>{{cite journal |author= Parenti, P. |year=2019 |title=An annotated checklist of the fishes of the family Sparidae |journal=FishTaxa |volume=4 |issue=2 |pages=47–98 |url= https://fishtaxa.com/menuscript/index.php/ft/article/view/49/52}}</ref> but the 5th edition of Fishes of the World does not recognise subfamilies within the Sparidae.<ref name = Nelson5/>
==Etymology== ''Gymnocrotaphus'' combines ''gymnos'', meaning naked, and ''crotaphus'' meaning "cheek", a reference to the lack of scales on the cheeks of this species. The [[Specific name (zoology)|specific name]], ''curvidens'', means "curved teeth", an allusion to the curved incisor-like teeth in rows in the front of each jaw.<ref name = ETYFish>{{cite web |url=https://etyfish.org/acanthuriformes6/ |title=Order ACANTHURIFORMES (part 6): Families GERREIDAE, LETHRINIDAE, NEMIPTERIDAE and SPARIDAE |date=12 January 2024 |access-date=28 January 2024 |author=Christopher Scharpf |work=The ETYFish Project Fish Name Etymology Database |publisher=Christopher Scharpf}}</ref>
==Description== ''Gymnocrotaphus'' has a naked head, except for some scales on the [[gill cover]]. There is a band of curved [[incisor]]-like teeth in each jaw with a band of smaller conical teeth inside this and the very small [[Molar (tooth)|molar]]-like teeth inside those. There are 10 spines and 11 or 12 soft rays supporting the [[dorsal fin]] while the [[anal fin]] is supported by 3 spines and 9 or 10 soft rays. The body is rather plump and deep, its depth fitting into its [[standard length]] 2.3 times. The dorsal profile of the headis concave in front of the eyes, and just above the eyes too. In life the colour of the body is coppery brown with a bluish grey head and blue eyes. Along each scale row there are orange lines.<ref name = WIOF>{{cite book |author=Yukio Iwatsuki |author2=Phillip C Heemstra |name-list-style=and |chapter=Family Sparidae |pages=284–315 |title=Coastal Fishes of the Western Indian Ocean |volume=3 |editor1=[[Phil Heemstra|Phillip C Heemstra]] |editor2=Elaine Heemstra |editor3=David A Ebert |editor4=Wouter Holleman |editor5=[[John Ernest Randall|John E Randall]] |year=2022 |isbn=978-1-990951-32-9 |publisher=South African Institute for Aquatic Biodiversity |url=https://saiab.ac.za/wp-content/uploads/2022/11/1._wiof_volume_3_text.pdf}}</ref> This species has a maximum published [[total length]] of {{cvt|50|cm}}.<ref name = Fishbase>{{Fishbase|Gymnocrotaphus|curvidens|month=October|year=2023}}</ref>
==Distribution and habitat== ''Gymnoctotaphus'' is endemic to the southeastern Atlantic and southwestern Indian Oceans where it is endemic to the coasts of South Africa from [[False Bay]] in the [{Western Cape to [[Port St. Johns]] in the [[Eastern Cape]].<ref name = WIOF/> This species is found at depths between {{cvt|1|and|80|m}} on shallow reefs.<ref name = iucn/>
==Biology== ''Gymnocrotaphus'' is an omnivorous, feeding on [[sea squirt]]s, [[bryozoa]]ns, [[Polychaete|polychaetes]], [[algae]] and [[Crustacean|crustaceans]]. It is a sedentary species which tends to stay close to the reef in crevices and overhangs.<ref name="SANBI" >{{cite web |url=http://speciesstatus.sanbi.org/assessment/last-assessment/02917/ |title=Red List of South African Species |date=December 2000 |publisher=SANBI |access-date=24 August 2023 }}</ref><ref name="Branch et al 2010" >{{cite book|last1=Branch |first1=G.M. |last2=Branch |first2=M.L. |last3=Griffiths |first3=C.L. |last4=Beckley |first4=L.E. |date=2010 |title=Two Oceans: a guide to the marine life of southern Africa |edition=2nd |publisher=Struik Nature |location=Cape Town |isbn=978-1-77007-772-0}}</ref><ref name="Jones 2008" >{{cite book|last=Jones |first=Georgina |title=A field guide to the marine animals of the Cape Peninsula |publisher=SURG |location=Cape Town |year=2008 |isbn=978-0-620-41639-9 }}</ref> Little is known about the biology of this species but it is thought it may be [[Sequential hermaphroditism|hermaphroditic]].<ref name = iucn/>
==Economic importance== Caught by shore anglers and spearfishers, with bag limit, prohibited for sale.<ref name="SANBI" />
==Conservation status== IUCN Status: Least concern. This species is considered to be effectively protected by no-take MPAs over its entire distributional range.<ref name="SANBI" />
==References== {{Reflist}} {{Taxonbar|from1=Q2507192|from2=Q2108876}}
[[Category:Fish described in 1858]] [[Category:Fish of South Africa]] [[Category:Sparidae]]