Hydrolycus armatus

Hydrolycus armatus
Adult in Berlin Aquarium, Germany
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Cynodontidae
Genus: Hydrolycus
Species:
H. armatus
Binomial name
Hydrolycus armatus
(Jardine, 1841)
Synonyms[2]
  • Hydrocyon armuatus Jardine, 1841

Hydrolycus armatus is a species of dogtooth characin found in freshwater of tropical South America.[3] It is sometimes known as the black-tailed payara, payara,[1] or harm,[4][5][6] a name it shares with the related H. scomberoides.

This predatory fish occasionally makes its way into the aquarium trade, but it requires a very large tank.[4][7] In its native range it is considered a major gamefish.[6][7]

Distribution and habitat

This species of fish is found in the Amazon, Orinoco and Essequibo basins in tropical South America.[3][8] They are found in several different freshwater habitats, but often in fast-flowing water.[6][9] They are typically found in deeper waters during the day.[9] The species is locally common; in a major study of a Venezuelan floodplain river, 13 of the collected fish were H. armatus, and the species was particularly common in creeks and lagoons.[10] At least some populations are migratory.[9]

Description

Hydrolycus armatus are overall silvery. In adults the base of the tail and anal fin is pale yellowish, and the distal part is blackish, contrasting with a narrow white edge at the very tip (unique among Hydrolycus species).[4][8][11]

Hydrolycus armatus (top), Rhaphiodon vulpinus (bottom)

A typically reported maximum total length of this fish is 89 cm (2 ft 11 in),[3] but records show specimens up to 95 cm (3 ft 1 in) in Venezuela[5] and more than 100 cm (3.3 ft) in Brazil.[6] It typically weighs up to 8.5 kg (18 lb 12 oz),[3] but can reach almost 18 kg (40 lb).[6] It has frequently been confused with the generally smaller H. scomberoides.[4][8] H. armatus reaches maturity when at least 30 cm (1 ft) long.[9] Like other dogtooth characins, it has very long pointed canine teeth. In H. armatus these can surpass 5 cm (2 in) in length in large individuals.[5] These are used for spearing their prey, usually other fish.[11]

References

  1. ^ a b Salvador, G.N. (2023). "Hydrolycus armatus". IUCN Red List of Threatened Species. 2023: e.T49829538A91630365. doi:10.2305/IUCN.UK.2023-1.RLTS.T49829538A91630365.en. Retrieved 24 June 2024.
  2. ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Species in the genus Hydrolycus". Catalog of Fishes. California Academy of Sciences. Retrieved 17 July 2025.
  3. ^ a b c d Froese, Rainer; Pauly, Daniel (eds.). "Hydrolycus armatus". FishBase. January 2017 version.
  4. ^ a b c d "Hydrolycus armatus". SeriouslyFish. Retrieved 13 January 2017.
  5. ^ a b c "Payara Venezuela". OPEFE. Archived from the original on 7 August 2016. Retrieved 13 January 2017.
  6. ^ a b c d e "Payara—Hydrolycus armatus". Acute Angling. Archived from the original on 20 October 2017. Retrieved 19 October 2017.
  7. ^ a b Scott, B.M. (March 2007). "Taming the Untamable—Giant Payara!". TFH Magazine. Retrieved 19 October 2017.
  8. ^ a b c Toledo-Piza, M.; N.A. Menezes; G.M. Santos (1999). "Revision of the Neotropical fish genus Hydrolycus (Ostariophysi: Characiformes: Cynodontidae) with the description of two new species". Ichthyol. Explor. Freshwaters. 10 (3): 255–280.
  9. ^ a b c d van der Sleen, P.; J.S. Albert, eds. (2017). Field Guide to the Fishes of the Amazon, Orinoco, and Guianas. Princeton University Press. p. 155. ISBN 978-0691170749.
  10. ^ Layman, C.A..; K.O. Winemiller (2005). "Patterns of habitat segregation among large fishes in a Venezuelan floodplain river". Neotrop. Ichthyol. 3 (1): 111–117. doi:10.1590/S1679-62252005000100007.
  11. ^ a b "Subfamily Cynodontinae". OPEFE. Archived from the original on 20 August 2016. Retrieved 19 October 2017.