View source for Handfish

{{Short description|Family of fishes}}
{{use Australian English|date=December 2021}}
{{use dmy dates|date=December 2021}}
{{Automatic taxobox
| image = CSIRO ScienceImage 10 The Endangered Spotted Handfish.jpg
| image_caption = ''[[Brachionichthys hirsutus]]''
| name = Handfish
| fossil_range = {{fossilrange|55|0}} [[Lutetian]] to Present<ref>{{cite journal|last=Sepkoski |first=Jack |title=A compendium of fossil marine animal genera |journal=Bulletins of American Paleontology |volume=364 |pages=560 |date=2002 |url=http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class |url-status=dead |archive-url=https://web.archive.org/web/20080430004102/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class |archive-date=April 30, 2008 }}</ref>
| taxon = Brachionichthyidae
| authority = [[Theodore Gill|T. N. Gill]], 1878
| subdivision_ranks = Genera
| subdivision = see text
}}

'''Handfish''' are marine, [[Actinopterygii|ray-finned fishes]] belonging to the [[Family (biology)|family]] '''Brachionichthyidae''', a group that comprises five [[genera]] and 14 extant species and is classified within the suborder Antennarioidei in the order [[Anglerfishes|Lophiiformes, the anglerfishes]].<ref>{{cite journal|author1=Last, P.R.|author2=Gledhill, D.C.|year= 2009|title= A revision of the Australian handfishes (Lophiiformes: Brachionichthyidae), with descriptions of three new genera and nine new species|journal=Zootaxa|volume=2252|pages= 1–77|doi=10.11646/zootaxa.2252.1.1|url=http://www.mapress.com./zootaxa/2009/f/zt02252p077.pdf |doi-access=free}}</ref>  These [[benthic]], marine fish are unusual in the way that in addition to swimming, they also use their pectoral fins to "walk" on the sea floor.

==Taxonomy==
The handfishes<!-- multiple species --> were first proposed as a family, the Brachionichthyidae, in 1878 by  American [[ichthyologist]] [[Theodore Gill]].<ref name = VDLEF>{{cite journal | author1 = Richard van der Laan | author2 = William N. Eschmeyer | author3 = Ronald Fricke | name-list-style = amp |year=2014 | title = Family-group names of recent fishes | url = https://biotaxa.org/Zootaxa/article/view/zootaxa.3882.1.1/10480 | journal = Zootaxa | volume = 3882 | issue = 2 | pages = 1–230| doi = 10.11646/zootaxa.3882.1.1 | pmid = 25543675 | doi-access = free }}</ref> The Brachionichthyidae are classified within the [[suborder]] [[Antennarioidei]] within the [[Order (biology)|order]] Lophiiformes, the anglerfishes.<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=508–518 |isbn=978-1-118-34233-6 |lccn=2015037522 |oclc=951899884 |ol=25909650M |doi=10.1002/9781119174844}}</ref> The Brachionichthyidae is regarded as the most [[Basal (phylogenetics)|basal]] family within the suborder Antennarioidei.<ref name = Miya>{{cite journal|last=Miya|first=M.|author2=T. Pietsch|authorlink2=Theodore Wells Pietsch III |author3=J. Orr |author4=R. Arnold |author5=T. Satoh |author6=A. Shedlock |author7=H. Ho |author8=M. Shimazaki |author9=M. Yabe |title=Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective|journal=BMC Evolutionary Biology|year=2010|volume=10|issue=1 |page=58|doi=10.1186/1471-2148-10-58|pmid=20178642|pmc=2836326 |bibcode=2010BMCEE..10...58M |doi-access=free }}</ref>

==Genera==
The handfish family, Brachionichthyidae, contains these genera:<ref name = Nelson5/><ref name = CofF>{{Cof family|family=Brachionichthyidae|access-date=13 March 2024}}</ref>

{{Linked genus list
| Brachionichthys | [[Pieter Bleeker|Bleeker]], 1854
| Brachiopsilus | [[Peter R. Last|Last]] & [[Daniel C. Gledhill|Gledhill]], 2009
| {{extinct}}Histionotophorus | [[Charles R. Eastman|Eastman]], 1904<ref name = pbdb>{{cite web |url=https://paleobiodb.org/classic/basicTaxonInfo?taxon_no=352295 |title=†''Histionotophorus'' Eastman 1904 (anglerfish) |access-date=13 March 2024 |publisher=Paleobiology Database}}</ref>
| Pezichthys | Last & Gledhill, 2009
| Sympterichthys | [[Theodore Gill|Gill]], 1878
| Thymichthys | Last & Gledhill, 2009
}}
{{extinct}} = Extinct

==Distribution==
Handfish are found today in the coastal waters of southern and eastern [[Australia]] and around the island state of [[Tasmania]]. This is the most species-rich of the few marine fish families [[Endemism|endemic]] to the Australian region, with all but three species found there.<ref name=foafam>{{cite web| url=https://fishesofaustralia.net.au/home/family/169#moreinfo| website= Fishes of Australia | publisher= [[Museums Victoria]]|title=Family Brachionichthyidae| access-date=29 December 2021}} Text may have been copied from this source, which is available under a [[File:CC-BY icon.svg|50px]] [https://creativecommons.org/licenses/by/3.0/au/ Attribution 3.0 Australia (CC BY 3.0 AU)] licence.</ref> Fourteen species of handfish are found around Tasmania.<ref name=rarepink/>

The biology of handfishes is poorly known and their typically small population sizes and restricted distributions make them highly vulnerable to disturbance. Some species are considered to be critically endangered.<ref name=j1/>

==Anatomy==
Handfish  grow up to {{convert|15|cm|abbr=on}} long, and have skin covered with [[Dermal denticle|denticle]]s (tooth-like [[scale (zoology)|scale]]s), giving them the alternative name warty anglers'.  They are slow-moving fish that prefer to "walk" rather than swim, using their modified [[pectoral fin]]s to move about on the sea floor. These highly modified fins have the appearance of hands, hence their scientific name, from [[Latin]] ''bracchium'' meaning "arm" and [[Greek language|Greek]] ''ichthys'' meaning "fish".{{cn|date=December 2021}}

Like other anglerfish, they possess an [[Anglerfish#Predation|illicium]], a modified [[dorsal fin]] ray above the mouth, but it is short and does not appear to be used as a [[fishing lure]].{{Dubious|date=January 2010}}[https://web.archive.org/web/20100612104847/http://www.arkive.org/spotted-handfish/brachionichthys-hirsutus/video-08.html] The second dorsal spine is joined to the third by a flap of skin, making a crest.<ref>{{cite web | url = http://tolweb.org/Brachionichthys/21996 | author = Pietsch, Theodore W.  | title = Brachionichthyidae | publisher = Tree of Life web project | year = 2005 | accessdate = 4 April 2006 }}</ref>

==Fossil record==
[[File:Histionotophorus bossani.JPG|thumb|right|Fossil of ''[[Histionotophorus|Histionotophorus bassani]]'']]
The prehistoric species, ''[[Histionotophorus|Histionotophorus bassani]]'', from the [[Lutetian]] of [[Monte Bolca]], is now considered to be a handfish, sometimes even being included in the genus ''[[Brachionichthys]]''. Considering the low extant diversity, restricted geographical distribution, and very meagre fossil record of antennarioids in general,  the existence of fossil representatives of the family Brachionichthyidae is unusual.<ref name=j1>{{cite journal|doi=10.1111/j.1096-3642.2009.00623.x|title=Eocene handfishes from Monte Bolca, with description of a new genus and species, and a phylogeny of the family Brachionichthyidae (Teleostei: Lophiiformes)|year=2010|last1=Carnevale|first1=Giorgio|last2=Pietsch|first2=Theodore W.|journal=Zoological Journal of the Linnean Society|volume=160|issue=4|pages=621–647|doi-access=}}</ref>

== Conservation status ==
[[File:Brachionichthys hirsutus RLS.jpg|[[Spotted handfish]], ''Brachionichthys hirsutus''|thumb]]
[[File:Sympterichthys politus.jpg|[[Red handfish]], ''Thymichthys politus''|thumb]]
[[File:FMIB 45786 Thymichthys verrucosus 2.jpg|Warty handfish, ''Thymichthys verrucosus''|thumb]]
In 1996, the [[spotted handfish]] (''Brachionichthys hirsutus'') was the first marine fish to be listed as critically endangered in the IUCN Red List.<ref name=":0" /><ref>Edgar, G., Stuart-Smith, R. & Last, P.R. (2020). ''Brachionichthys hirsutus''. The IUCN Red List of Threatened Species. {{doi|10.2305/IUCN.UK.2020-1.RLTS.T2958A121210485.en}}</ref> With its only habitat in the [[Derwent River, Tasmania|Derwent River]] estuary and surrounds, it is threatened by the [[Northern Pacific seastar in Australia|Northern Pacific seastar's invasion into southern Australian waters]]. The [[Northern Pacific seastar]] (''Asterias amurensis''), preys on not only the fish eggs,<ref>{{cite web|url= https://www.fishbase.de/summary/Brachionichthys-hirsutus.html |website=Fishbase|title=Brachionichtys-hirsutus}}</ref> but also on the sea squirts ([[ascidian]]s)<ref name=gisd>{{cite web | title=Asterias amurensis| website=Global invasive species database|publisher=[[Invasive Species Specialist Group]] (ISSG)| date=10 March 2010 | url=http://www.iucngisd.org/gisd/speciesname/Asterias+amurensis | access-date=20 February 2021}}</ref> that help to form the [[Substrate (marine biology)|substrate]] that the fish spawn on.<ref name=abc2021>{{cite web | last=MacDonald | first=Lucy | title=Volunteers hope efforts to remove invasive northern Pacific seastar will make a difference  | website=ABC News| publisher= [[Australian Broadcasting Corporation]] | date=20 February 2021 | url=https://www.abc.net.au/news/2021-02-20/tas-invasive-northern-pacific-seastar-removal-efforts/13164004 | access-date=20 February 2021}}</ref>

The cause of the decline in spotted handfish is unclear. Suggested causes may include disturbance of benthic communities and predation on egg masses by the introduced [[northern Pacific seastar]], habitat modification through increased [[silt]]ation, [[heavy metal contamination]], or urban [[effluent]]. The lack of a pelagic larval stage and low rates of dispersal may be responsible for their restricted distributions, and may also have an impact on their ability to recolonise areas where they once occurred.<ref name=foafam/>

In March 2020, the [[smooth handfish]] (''Sympterichthys unipennis)'' was declared extinct in the [[IUCN Red List]].<ref>Last, P.R., Edgar, G. & Stuart-Smith, R. (2020). ''Sympterichthys unipennis''. The IUCN Red List of Threatened Species. {{doi|10.2305/IUCN.UK.2020-1.RLTS.T123423283A123424374.en}}</ref><ref name=":0">{{Cite journal|title=Smooth Handfish Extinction Marks a Sad Milestone|url=https://www.scientificamerican.com/article/smooth-handfish-extinction-marks-a-sad-milestone/|volume=323|issue= 1|pages= 14 |date=July 2020|author=Shiffman, David|journal=Scientific American|doi=10.1038/scientificamerican0720-14a |pmid=39014622 |url-access=subscription}}</ref> Once common enough to be one of the first fish to be described by European explorers of Australia, but not seen for well over a century, this is the first modern-day marine fish to be officially declared extinct.<ref name=":0" /> However, this status was reversed in September 2021 and classified as Data Deficient, as survey data were insufficient to confirm that status.<ref name=abcredlist>{{cite web | last=Clarke | first=Melissa | title=Bogong moth, grey-headed flying fox listed as endangered by IUCN  | website=ABC News| publisher= [[Australian Broadcasting Corporation]] | date=9 December 2021 | url=https://www.abc.net.au/news/2021-12-09/bogong-moth-grey-headed-flying-fox-endangered/100687642 | access-date=30 December 2021}}</ref><ref name=iucn2021>{{cite web | title=The IUCN Red List of Threatened Species | website=IUCN Red List of Threatened Species | date=9 September 2021 | url=https://www.iucnredlist.org/en | access-date=30 December 2021}}</ref>

In October 2021, the endangered and very rare [[pink handfish]] (''Brachiopsilus dianthus''<ref name=foapink>{{cite web| url=https://fishesofaustralia.net.au/home/species/2676| website= Fishes of Australia | publisher= [[Museums Victoria]]|title=Pink Handfish, Brachiopsilus dianthus Last & Gledhill 2009| access-date=29 December 2021}} [[File:CC-BY icon.svg|50px]] [https://creativecommons.org/licenses/by/3.0/au/ Attribution 3.0 Australia (CC BY 3.0 AU)] licence.</ref>) was seen for the first time since 1999, in footage from a camera placed on the sea bed off Tasmania at a depth of {{cvt|150|m|ft|abbr=on}}. Prior to this sighting, this species was assumed to be confined to shallow waters. The discovery that it has a greater range than previously thought may give cause for optimism regarding its survival.<ref name=rarepink>{{cite web | title=Rare pink handfish spotted in Australia for first time in decades | url=https://www.bbc.co.uk/news/world-australia-59778215 | date=24 December 2021 | website=[[BBC News]]}}</ref>

===Current status of species===
{{as of|December 2021}} three species of handfish are listed as [[threatened species|threatened]] under the ''[[Environment Protection and Biodiversity Conservation Act 1999]]'' (EPBC Act) and the IUCN:<ref name=foafam/>
*''[[Brachionichthys hirsutus]]'', spotted handfish – [[critically endangered]] under EPBC Act and IUCN;<ref name=spratspot>{{cite web | title=Brachionichthys hirsutus — Spotted Handfish| website=[[Species Profile and Threats Database]]| series=SPRAT Profile | url=https://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=64418|publisher= [[Department of Agriculture, Water and the Environment]] (Australia) | access-date=30 December 2021}} [[File:CC-BY icon.svg|50px]] [https://creativecommons.org/licenses/by/4.0 Attribution 4.0 International  (CC BY 4.0)] licence.</ref>

*''[[Thymichthys politus]]'',{{efn|Fishes of Australia says ''Brachionichthys politus'', red handfish, and it appears from the Australian Govt [[Species Profile and Threats Database]] that  change of name occurred  from this name to the current one around 2011, with the [[EPBC Act]] updated accordingly.<ref name=spratred>{{cite web | title=Thymichthys politus - Red Handfish | website=[[Species Profile and Threats Database]]| series=SPRAT Profile | url=https://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=83756|publisher= [[Department of Agriculture, Water and the Environment]] (Australia) | access-date=30 December 2021}} [[File:CC-BY icon.svg|50px]] [https://creativecommons.org/licenses/by/4.0 Attribution 4.0 International  (CC BY 4.0)] licence.</ref>}} red handfish – Critically Endangered under EPBC Act and IUCN;<ref name=spratred/> and

*''[[Brachiopsilus ziebelli]]'', Ziebell's handfish – vulnerable under EPBC Act, critically endangered under IUCN.<ref name=spratziebell>{{cite web | title=Brachiopsilus ziebelli — Ziebell's Handfish, Waterfall Bay Handfish| website=[[Species Profile and Threats Database]]| series=SPRAT Profile | url=https://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=83757|publisher= [[Department of Agriculture, Water and the Environment]] (Australia) | access-date=30 December 2021}} [[File:CC-BY icon.svg|50px]] [https://creativecommons.org/licenses/by/4.0 Attribution 4.0 International  (CC BY 4.0)] licence.</ref> 

All three of the above are listed as endangered under the Tasmanian ''[[Threatened Species Protection Act 1995]]'',<ref name=spratspot/><ref name=spratred/><ref name=spratziebell/> and all handfish species are protected under the Tasmanian ''Living Marine Resources Management Act 1995'', which prohibits their collection in state waters without a permit.<ref name=foafam/>

==Notes==
{{notelist}}

== References ==
{{Reflist}}

== External links ==
{{Commons category|Brachionichthyidae}}
{{Wikispecies|Brachionichthyidae}}
*Bradley, Carolyn. [https://web.archive.org/web/20150320094707/http://news.nationalgeographic.com/news/2010/05/photogalleries/100524-new-species-handfish-walk-science-pictures/?now=2010-05-24-00:01 ''Pictures: Nine Fish With "Hands" Found to Be New Species''] (''[[National Geographic]]'', 25 May 2010) - Pink handfish formally identified.

{{Taxonbar|from=Q1574997}}
{{Authority control}}

[[Category:Antennarioidei]]
[[Category:Brachionichthyidae]]
[[Category:Marine fish of Australia|&nbsp;]]
[[Category:Extant Lutetian first appearances]]
[[Category:Taxa named by Theodore Gill]]