The shortjaw kōkopu (Galaxias postvectis) is a galaxiid ray-finned fish, endemic to New Zealand.[2][3] They are large, scaleless fish which inhabit stable pools in cascading, bouldery streams with forest cover.[4] Shortjaw kōkopu are amphidromous, with the fry going to sea after hatching, and returning as juveniles to fresh water where they grow to adulthood.[4] They may grow to a maximum of 350 mm (14 in) in total length, but more commonly reach 150–200 mm (5.9–7.9 in).[4]

Shortjaw kōkopu
Adult shortjaw kōkopu
Adult shortjaw kōkopu showing orange colouration
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Galaxiiformes
Family: Galaxiidae
Genus: Galaxias
Species:
G. postvectis
Binomial name
Galaxias postvectis

The shortjaw kōkopu live in microhabitats that have more large particles at the bed of the body of water (substrates) and more places to seek safety compared to all nearby possible habitats.[5][6] During the night, they remain in calmer areas like pools, whereas during the day shortjaw kōkopu spend their time in places with large substrates and a more tumultuous water surface, staying in both flow channel and pool habits.[7]

In 2023 a newly recorded population of this species was detected in the Kopuawhara catchment north of Māhia Peninsula in Hawkes Bay using environmental DNA.[8]

References

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  1. ^ West, D.; David, B.; Hitchmough, R.; Champion, P.; Ling, N.; Allibone, R.; Crow, S. (2014). "Galaxias postvectis". IUCN Red List of Threatened Species. 2014: e.T8813A3147213. doi:10.2305/IUCN.UK.2014-3.RLTS.T8813A3147213.en. Retrieved 12 November 2021.
  2. ^ "Shortjaw kōkopu". NIWA. 2009-06-04. Retrieved 2021-07-15.
  3. ^ "Galaxias postvectis, Shortjaw kokopu : fisheries". fishbase.mnhn.fr. Retrieved 2023-07-30.
  4. ^ a b c McDowall, R.M. (2000). The Reed Field Guide to New Zealand Freshwater Fishes. Auckland: Reed. ISBN 0 7900 0725 8.
  5. ^ McQueen, Stella (2013). A photographic guide to freshwater fishes of New Zealand. Rod Morris. Auckland. ISBN 978-1-86966-386-5. OCLC 858411018.{{cite book}}: CS1 maint: location missing publisher (link)
  6. ^ "Shortjaw kokopu". NIWA. 2007-02-28. Retrieved 2023-07-30.
  7. ^ McEwan, Amber Julie; Joy, Michael Kevin (August 2014). "Diel habitat use of two sympatric galaxiid fishes (Galaxias brevipinnis and G. postvectis) at two spatial scales in a small upland stream in Manawatu, New Zealand". Environmental Biology of Fishes. 97 (8): 897–907. doi:10.1007/s10641-013-0191-x. ISSN 0378-1909.
  8. ^ "Regional council detects rare fish in Hawke's Bay using DNA traces". NZ Herald. 2023-07-31. Retrieved 2023-07-30.
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