Thered handfish(Thymichthys politus) is a species of marineray-finned fishesbelonging to thefamilyBrachionichthyidae,the handfishes. Like all members of the handfish family this fish isendemicto Australia. TheIUCNclassify the red handfish asCritically Endangered.

Red handfish
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Lophiiformes
Family: Brachionichthyidae
Genus: Thymichthys
Species:
T. politus
Binomial name
Thymichthys politus
(Richardson,1844)
Synonyms
  • Cheironectes politusRichardson, 1844
  • Brachionichthys politus(Richardson, 1844)
  • Sympterichthys politus(Richardson, 1844)

Taxonomy

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The red handfish was first formallydescribedasCheironectes politusin 1844 by the Scottishnaval surgeon,Arctic explorerandnaturalistJohn Richardsonwith itstype localitygiven as theActeon IslandsoffTasmania.[2]The Australian zoologists Peter R, Last and Daniel C. Gledhill created the new genusThymichthysthey designatedCheironectes politusas thetype species.[3]This genus is classified within the family Brachionichthyidae which the 5th edition ofFishes of the Worldclassifies the family Brachionichthyidae within thesuborderAntennarioideiwithin theorderLophiiformes, the anglerfishes.[4]

Etymology

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The red handfish has the genus nameThymichthyswhich is a combination ofthymos,meaning "warty growths", andichthys,which means "fish". This is an allusion to the warty protuberances on the skin of this fish. Thespecific name,politus,means "polished", an allusion Richardson did not explain but it is thought to be to the smoothness of its skin to the touch or its bright colouration.[5]

Description

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The red handfish is distinguished by its small, flattened wart-like protuberances that cover its body and red colouration. Two colourmorphsexist, a bright red morph with red colour on both body and fins, with a black line separating the white fin edges and a mottled morph with pink body covered in many red patches, with translucent pink fins expressing some bright red patches. Theymeasurean average standard length of 61.4 mm (2.4 in) and an average total length of 80.1 mm (3.2 in).[3]They use their hand-like fins to crawl rather than swim.[6]

Ecology and behavior

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Distribution and habitat

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Historically, the species was found in multiple subpopulations in Tasmania, includingPort Arthur,Fortescue Bay,theActaeon Islands,D'Entrecasteaux Channel,and theForestier Peninsula.Currently, the species has been found only on two small reefs inFrederick Henry Bay.These species typically reside in reef sand junctions, where there is an abundance of sand and rocks. Themacro-algaethat covers the rock allows them to easily blend in with their environment. These reefs measure no more than 50 m in diameter with a circular area of no more than 75 m. It is found at depth ranges from 1 m up to 20 m.[3]

Reproduction

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Their limited range is attributed to the low reproduction and dispersal rate. Unlike other fish they recruit directly on thebenthos.[7]Females lay their eggs at the base of seagrass from august through to October. Each egg mass contains 30- 60 eggs that are connected bytubulesbound together. These eggs are then guarded by the adults until they hatch.[8]

Diet

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Little is known about their diet but that it consists of animals that live in the benthos. Their diet consists of smallcrustaceansandpolychaeteworms.[9]

Conservation

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In November 2023, researchers at Tasmania’s Institute for Marine and Antarctic Studies (IMAS) found a cluster of 21 yellow eggs in one of their tanks for red handfish. One of the researchers said “We’re delighted to announce the safe arrival of 21 baby red handfish.” This is the second time red handfish have been bred in captivity, with the previous time being in 2021.[10]

Threats

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General threats to red handfish include small, very fragmented populations and local increases in density of native purple urchins. Native purple urchins overgraze the seaweed habitat required for shelter and spawning for the red handfish. Summer observations of low seaweed on urchin barrens suggest that loss of seaweed habitat might represent a key threat to long term viability of the population In addition, the close vicinity of urban development increases the risk ofnutrient runoff,pollution, siltation, and turbidity. This results in habitat degradation through the ruin of the red handfish preferred seaweed habitat. Loss of spawning substrate limit the red handfish as to where their eggs can attach resulting in the eggs being lost to the current. Limitations include difficulty spotting the species among its habitat. Red handfish may face severe pressure due to direct environmental consequences of warming coastal waters, including potential implications on reproduction, egg development, feeding, and escape reaction, which are currently unknown.[1]

Status

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The red handfish is classed asCritically Endangeredunder the AustralianEnvironment Protection and Biodiversity Conservation Act 1999(EPBC Act) and by theIUCN,and as Endangered under Tasmania'sThreatened Species Protection Act 1995.[7]

References

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  1. ^abStuart-Smith, R.; Edgar, G. &Last, P.R.(2020)."Thymichthys politus".IUCN Red List of Threatened Species.2020:e.T123423510A123424379.doi:10.2305/IUCN.UK.2020-1.RLTS.T123423510A123424379.en.Retrieved22 March2024.
  2. ^Eschmeyer, William N.;Fricke, Ron & van der Laan, Richard (eds.)."Species in the genusThymichthys".Catalog of Fishes.California Academy of Sciences.Retrieved22 March2024.
  3. ^abcLast, P.R. & Gledhill, D.C (2009). "A revision of the Australian handfishes (Lophiiformes: Brachionichthyidae), with descriptions of three new genera and nine new species.".Zootaxa.2252(1).Magnolia Press:1–77.doi:10.11646/zootaxa.2252.1.
  4. ^Nelson, 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.
  5. ^Christopher Scharpf (14 November 2022)."Order LOPHIIFORMES (part 1): Families LOPHIIDAE, ANTENNARIIDAE, TETRABRACHIIDAE, LOPHICHTHYIDAE, BRACHIONICHTHYIDAE, CHAUNACIDAE and OGCOCEPHALIDAE".The ETYFish Project Fish Name Etymology Database.Christopher Scharpf.Retrieved18 March2024.
  6. ^Jeffery, Michael I.; Firestone, Jeremy; Bubna-Litic, Karen, eds. (2008),"Sanctuaries, Protected Species, and Politics – How Effective Is Australia at Protecting Its Marine Biodiversity under the Environment Protection and Biodiversity Conservation Act 1999?",Biodiversity Conservation, Law + Livelihoods,Cambridge: Cambridge University Press, pp. 280–305,doi:10.1017/cbo9780511551161.018,ISBN9780511551161,retrieved12 April2023
  7. ^abThe PLOS ONE Staff (26 September 2018)."Correction: Local densities and habitat preference of the critically endangered spotted handfish (Brachionichthys hirsutus): Large scale field trial of GPS parameterised underwater visual census and diver attached camera".PLOS ONE.13(9): e0205040.doi:10.1371/journal.pone.0205040.ISSN1932-6203.PMC6157897.PMID30256847.
  8. ^Jeffery, Michael I.; Firestone, Jeremy; Bubna-Litic, Karen, eds. (2008),"Sanctuaries, Protected Species, and Politics – How Effective Is Australia at Protecting Its Marine Biodiversity under the Environment Protection and Biodiversity Conservation Act 1999?",Biodiversity Conservation, Law + Livelihoods,Cambridge: Cambridge University Press, pp. 280–305,doi:10.1017/cbo9780511551161.018,ISBN9780511551161,retrieved12 April2023
  9. ^"Tasmania (Australia), Bass Strait Coast".Journal of Coastal Research.100(sp2). 31 December 2022.doi:10.2112/jcr-si100-flat-058.1.ISSN0749-0208.
  10. ^"Researchers Look In Tank And See Promising Cluster Of Nearly-Extinct Babies - The Dodo".thedodo.Retrieved3 December2023.


These sources are from the science citation index. Specifically, they were found through the University of Illinois at Chicago database.