Silver arowana

Silver arowana
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Osteoglossiformes
Family:	Osteoglossidae
Genus:	Osteoglossum
Species:	O. bicirrhosum
Binomial name
Osteoglossum bicirrhosum Cuvier (ex Vandelli), 1829

The silver arowana (Osteoglossum bicirrhosum) is a South American freshwater bony fish of the family Osteoglossidae. Silver arowanas are sometimes kept in aquariums, but they are predatory and require a very large tank.^[2]

The generic name Osteoglossum means "bone-tongued" and the specific name bicirrhosum means "two barbels" (from the Greek language).

Range and habitat

This South American species is native to the Amazon, Essequibo and Oyapock basins.^[3][4] It is absent from the Rio Negro basin, except the Branco River, which is inhabited by both silver and black arowanas.^[4]

The silver arowana occurs in both black- and whitewater habitats, including flooded forests.^[2][5]

Description

This fish has relatively large scales, a long body, and a tapered tail, with the dorsal and anal fins extending all the way to the small caudal fin, with which they are nearly fused. Its maximum total length is typically considered to be 0.9 m (3.0 ft),^[3] but there are reports of individuals up to 1.2 m (3.9 ft).^[2] Unlike the black arowana, the silver arowana has the same coloring throughout its lifespan. Adults of the two species are very similar, but can be separated by meristics.^[6]

Arowanas are sometimes called 'dragon fish' by aquarists because their shiny, armor-like scales and double barbels are reminiscent of descriptions of dragons in East Asian folklore.^[7]

Behavior

The species is also called 'water monkey' because of its ability to jump out of the water and capture its prey.^[8] It usually swims near the water surface waiting for potential prey. Although specimens have been found with the remains of birds, bats, mice, and snakes in their stomachs, its main diet consists of snails, crustaceans (such as crabs), insects (such as beetles), spiders, smaller fish, and other animals that float on the water surface, for which purpose its drawbridge-like mouth is adapted.^[9][10][11]

Conservation status

The silver arowana is not currently listed on any CITES appendix^[12] and is listed as Least Concern on the IUCN Red List.^[1] It is one of the most popular ornamental fish from South America, however, and therefore its conservation status merits attention.^[1][13] Other threats include droughts and deforestation, siltation and drainage of land for human use.^[1]

As reported by Environment News Service in August 2005, shared use of the silver arowana population was a cause for a dispute between Brazilian and Colombian authorities. Juvenile silver arowanas are caught in Colombia for sale as aquarium fish, while the people of Brazilian Amazonia catch adult fish for food. A sharp drop in the number of arowanas had caused Brazilian authorities to prohibit fishing of them between September 1 and November 15; the Colombians would prohibit capturing them between November 1 and March 15.^[14]

The silver arowana is often kept as a pet by experienced aquarists, being considered an accessible substitute for the Asian arowana, which is listed on CITES Appendix I and is therefore difficult and expensive to obtain legally.^[15]

See also

• List of freshwater aquarium fish species
• Asian arowana

References

1. Salvador, G.N. (2023). "Osteoglossum bicirrhosum". IUCN Red List of Threatened Species. 2023: e.T49830060A85282193. doi:10.2305/IUCN.UK.2023-1.RLTS.T49830060A85282193.en. Retrieved 14 January 2024.
2. Hill, N. (13 June 2016). "Predators: South American Arowana". Practical Fishkeeping. Retrieved 25 October 2017.
3. Froese, Rainer; Pauly, Daniel (eds.). "Osteoglossum bicirrhosum". FishBase. October 2017 version.
4. Escobar; Farias; Taphorn; Landines; Hrbek (2013). "Molecular diagnosis of the arowanas Osteoglossum ferreirai Kanazawa, 1966 and O. bicirrhossum (Cuvier, 1829) from the Orinoco and Amazon River basins". Neotrop. Ichthyol. 11 (2): 335–340. doi:10.1590/S1679-62252013000200011.
5. Saint-Paul; Zuanon; Correa; García; Fabré; Berger; Junk (2000). "Fish communities in central Amazonian white-and blackwater floodplains". Environmental Biology of Fishes. 57 (3): 235–250. doi:10.1023/a:1007699130333. S2CID 25361090.
6. Schofield, P.J.; L.G. Nico; P.L. Fuller; W.F. Loftus; M. Neilson (6 August 2013). "Osteoglossum bicirrhosum". U.S. Geological Survey, Nonindigenous Aquatic Species Database. Retrieved 25 October 2017.
7. Bauer, Sophie (2019-03-14). "Amazonian dragon fish star in Chinese aquariums". Dialogue Earth. Retrieved 2024-08-04.
8. Voigt, Emily (2016-05-24). The Dragon Behind the Glass: A True Story of Power, Obsession, and the World's Most Coveted Fish. Simon and Schuster. p. 16. ISBN 978-1-4516-7896-3.
9. Mikula P (2015). "Fish and amphibians as bat predators". European Journal of Ecology. 1 (1): 71–80. doi:10.1515/eje-2015-0010.
10. Julia Tovar Verba; Manoela Lima de Oliveira Borges; Maria Nazareth Ferreira da Silva; Lorena Costa Pinto; José Gurgel Rabello Neto (2018). "Mice on menu: opportunistic feeding behaviour of the Amazonian silver arowana Osteoglossum bicirrhosum". Journal of Fish Biology. 93 (1): 132–133. doi:10.1111/jfb.13665. PMID 29934944. S2CID 49378286.
11. Birchmeier, Kelly. "Osteoglossum bicirrhosum (Arawana)". Animal Diversity Web. Retrieved 2024-08-04.
12. CITES Appendices. 25 November 2023. Retrieved 14 January 2024.
13. International meeting on ornamental fish boosts regional conservation and sustainable resource management initiatives (WWF)
14. Brazil, Colombia at Odds Over Silver Amazon Fish. A meeting between the representatives of the Amazon Basin countries in August 2005 was meant to discuss the dispute.
15. "Silver arowana (Osteoglossum bicirrhosum)". JungleDragon. Retrieved 2024-08-04.

External links

• "Osteoglossum bicirrhosum". Integrated Taxonomic Information System. Retrieved 19 March 2006.
• Media related to Silver arowana at Wikimedia Commons