Handfishare marineray-finned fishesbelonging to thefamilyBrachionichthyidae,a group which comprises fivegeneraand 14 extant species and which is classified within the suborder Antennarioidei in the orderLophiiformes, the anglerfishes.[2]Thesebenthicmarine fish are unusual in the way they propel themselves by walking on the sea floor rather than swimming.
| Handfish | |
|---|---|
| |
| Brachionichthys hirsutus | |
Scientific classification
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Lophiiformes |
| Suborder: | Antennarioidei |
| Family: | Brachionichthyidae T. N. Gill,1878 |
| Genera | |
|
see text | |
Taxonomy
editThe handfish were first proposed as a family, Brachionichthyidae, in 1878 by the AmericanichthyologistTheodore Gill.[3]The Brachionichthyidae is classified within thesuborderAntennarioideiwithin theorderLophiiformes, the anglerfishes.[4]The Brachionichthyidae is regarded as the mostbasalfamily within the suborder Antennarioidei.[5]
Genera
editThe handfish family, Brachionichthyidae, contains the following genera:[4][6]
- BrachionichthysBleeker,1854
- BrachiopsilusLast&Gledhill,2009
- †HistionotophorusEastman,1904[7]
- PezichthysLast & Gledhill, 2009
- SympterichthysGill,1878
- ThymichthysLast & Gledhill, 2009
†= Extinct
Distribution
editHandfish are found today in the coastal waters of southern and easternAustraliaand around the island state ofTasmania.This is the most species-rich of the few marine fish familiesendemicto the Australian region, with all but three species found there.[8]There are 14 species of handfish around Tasmania.[9]
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.[10]
Anatomy
editHandfish grow up to 15 cm (5.9 in) long, and have skin covered withdenticles(tooth-likescales), giving them the alternative namewarty anglers.They are slow-moving fish that prefer to 'walk' rather than swim, using their modifiedpectoral finsto move about on the sea floor. These highly modified fins have the appearance of hands, hence their scientific name, fromLatinbracchiummeaning "arm" andGreekichthysmeaning "fish".[citation needed]
Like other anglerfish, they possess anillicium,a modifieddorsal finray above the mouth, but it is short and does not appear to be used as afishing lure.[dubious–discuss][1]The second dorsal spine is joined to the third by a flap of skin, making a crest.[11]
Fossil record
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The prehistoric species,Histionotophorus bassani,from theLutetianofMonte Bolca,is now considered to be a handfish, sometimes even being included in the genusBrachionichthys.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.[10]
Conservation status
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In 1996, thespotted handfish(Brachionichthys hirsutus) was the first marine fish to be listed as critically endangered in the IUCN Red List.[12][13]With its only habitat in theDerwent Riverestuary and surrounds, it is threatened by theNorthern Pacific seastar's invasion into southern Australian waters.TheNorthern Pacific seastar(Asterias amurensis), preys on not only the fish eggs,[14]but also on the sea squirts (ascidians)[15]that help to form thesubstratethat the fish spawn on.[16]
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 introducednorthern Pacific seastar,habitat modification through increasedsiltation,heavy metal contaminationor urbaneffluent.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 handfishes ability to recolonise areas where they once occurred.[8]
In March 2020, thesmooth handfish(Sympterichthys unipennis)was declared extinct in theIUCN Red List.[17][12]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.[12]However, this was reversed in September 2021, as there is not sufficient data to confirm this status.[18][19]
In October 2021, the endangered and very rarepink handfish(Brachiopsilus dianthus[20]) was seen for the first time since 1999, in footage from a camera placed on the sea bed off Tasmania at a depth of 150 m (490 ft). Prior to this sighting, it had been assumed that this species was confined to shallow waters. The discovery that it has a greater range than previously thought may give cause for optimism regarding its survival.[9]
Current status of species
editAs of December 2021[update]three species of handfish are listed asthreatenedunder theEnvironment Protection and Biodiversity Conservation Act 1999(EPBC Act) and the IUCN:[8]
- Brachionichthys hirsutus,spotted handfish –Critically Endangeredunder EPBC Act and IUCN;[21]
- Thymichthys politus,[a]red handfish – Critically Endangered under EPBC Act and IUCN;[22]and
- Brachiopsilus ziebelli,Ziebell's handfish – Vulnerable under EPBC Act, Critically Endangered under IUCN.[23]
All three of the above are listed as Endangered under the TasmanianThreatened Species Protection Act 1995,[21][22][23]and all handfish species are protected under the TasmanianLiving Marine Resources Management Act 1995,which prohibits their collection in State waters without a permit.[8]
Footnotes
edit- ^Fishes of Australia saysBrachionichthys politus,red handfish, and it appears from the Australian GovtSpecies Profile and Threats Databasethat there has been a change of name from this name to the current one around 2011, with theEPBC Actupdated accordingly.[22]
References
edit- ^Sepkoski, Jack (2002)."A compendium of fossil marine animal genera".Bulletins of American Paleontology.364:560. Archived fromthe originalon 30 April 2008.
- ^Last, P.R.; Gledhill, D.C. (2009)."A revision of the Australian handfishes (Lophiiformes: Brachionichthyidae), with descriptions of three new genera and nine new species"(PDF).Zootaxa.2252:1–77.doi:10.11646/zootaxa.2252.1.1.
- ^Richard van der Laan; William N. Eschmeyer & Ronald Fricke (2014)."Family-group names of recent fishes".Zootaxa.3882(2): 1–230.doi:10.11646/zootaxa.3882.1.1.PMID25543675.
- ^abNelson, J.S.;Grande, T.C.; Wilson, M.V.H. (2016).Fishes of the World(5th ed.). Hoboken, NJ:John Wiley & Sons.pp. 508–518.doi:10.1002/9781119174844.ISBN978-1-118-34233-6.LCCN2015037522.OCLC951899884.OL25909650M.
- ^Miya, M.;T. Pietsch;J. Orr; R. Arnold; T. Satoh; A. Shedlock; H. Ho; M. Shimazaki; M. Yabe (2010)."Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective".BMC Evolutionary Biology.10(1): 58.Bibcode:2010BMCEE..10...58M.doi:10.1186/1471-2148-10-58.PMC2836326.PMID20178642.
- ^Eschmeyer, William N.;Fricke, Ron & van der Laan, Richard (eds.)."Genera in the family Brachionichthyidae".Catalog of Fishes.California Academy of Sciences.Retrieved13 March2024.
- ^"†HistionotophorusEastman 1904 (anglerfish) ".Paleobiology Database.Retrieved13 March2024.
- ^abcd"Family Brachionichthyidae".Fishes of Australia.Museums Victoria.Retrieved29 December2021.Text may have been copied from this source, which is available under a
Attribution 3.0 Australia (CC BY 3.0 AU)licence.
- ^ab"Rare pink handfish spotted in Australia for first time in decades".BBC News.24 December 2021.
- ^abCarnevale, Giorgio; Pietsch, Theodore W. (2010). "Eocene handfishes from Monte Bolca, with description of a new genus and species, and a phylogeny of the family Brachionichthyidae (Teleostei: Lophiiformes)".Zoological Journal of the Linnean Society.160(4): 621–647.doi:10.1111/j.1096-3642.2009.00623.x.
- ^Pietsch, Theodore W. (2005)."Brachionichthyidae".Tree of Life web project.Retrieved4 April2006.
- ^abcShiffman, David (July 2020)."Smooth Handfish Extinction Marks a Sad Milestone".Scientific American.323(1): 14.doi:10.1038/scientificamerican0720-14a.PMID39014622.
- ^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
- ^"Brachionichtys-hirsutus".Fishbase.
- ^"Asterias amurensis".Global invasive species database.Invasive Species Specialist Group(ISSG). 10 March 2010.Retrieved20 February2021.
- ^MacDonald, Lucy (20 February 2021)."Volunteers hope efforts to remove invasive northern Pacific seastar will make a difference".ABC News.Australian Broadcasting Corporation.Retrieved20 February2021.
- ^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
- ^Clarke, Melissa (9 December 2021)."Bogong moth, grey-headed flying fox listed as endangered by IUCN".ABC News.Australian Broadcasting Corporation.Retrieved30 December2021.
- ^"The IUCN Red List of Threatened Species".IUCN Red List of Threatened Species.9 September 2021.Retrieved30 December2021.
- ^"Pink Handfish, Brachiopsilus dianthus Last & Gledhill 2009".Fishes of Australia.Museums Victoria.Retrieved29 December2021.Attribution 3.0 Australia (CC BY 3.0 AU)licence.
- ^ab"Brachionichthys hirsutus — Spotted Handfish".Species Profile and Threats Database.SPRAT Profile.Department of Agriculture, Water and the Environment(Australia).Retrieved30 December2021.Attribution 4.0 International (CC BY 4.0)licence.
- ^abc"Thymichthys politus - Red Handfish".Species Profile and Threats Database.SPRAT Profile.Department of Agriculture, Water and the Environment(Australia).Retrieved30 December2021.Attribution 4.0 International (CC BY 4.0)licence.
- ^ab"Brachiopsilus ziebelli — Ziebell's Handfish, Waterfall Bay Handfish".Species Profile and Threats Database.SPRAT Profile.Department of Agriculture, Water and the Environment(Australia).Retrieved30 December2021.Attribution 4.0 International (CC BY 4.0)licence.
External links
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- Bradley, Carolyn.Pictures: Nine Fish With "Hands" Found to Be New Species(National Geographic,25 May 2010) - Pink handfish formally identified.