The black arowana (''Osteoglossum ferreirai'') is a South American freshwater

bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...

of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Osteoglossidae Osteoglossidae is a family of large-sized freshwater fish, which includes the arowanas. They are commonly known as bonytongues. The family has been regarded as containing two extant subfamilies Arapaiminae and Osteoglossinae, with a total of f ...

. Black arowanas are sometimes kept in

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

s, but they are predatory and require a very large tank. It is generally common, but large numbers are caught as food and for the aquarium fish trade.

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''ferreirai'' is named in honour of Alexandre Rodrigues Ferreira, the Portuguese-Brazilian naturalist who first reported this species.

Range and habitat

The black arowana is native to tropical South America where restricted to the Rio Negro basin, including the

Branco River The Branco River (; Engl: ''White River'') is the principal affluent of the Rio Negro from the north. Basin The river drains the Guayanan Highlands moist forests ecoregion. It is enriched by many streams from the Tepui highlands which separat ...

. Black arowanas were discovered in the 1970s in the

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

basins, but whether this is a natural population or the result of introductions by humans is disputed. It is essentially a sedentary (non-migratory) species of blackwater habitats. During the dry season it mostly inhabits backwaters, marginal lagoons and small tributaries, but it is often seen in

flooded forest Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are foun ...

s during the high water season.

Description

The black arowana has an elongated body and a tapered tail. Their maximum total length is typically considered to be , but there are reports of individuals up to . The juveniles are black with yellow markings down the length of the body, head and the tail. Once it reaches about , the markings disappear and the fish will develop a dark iridescent steel grey to blue coloration, hence its common name. Additionally, there are yellow and red outlining or the dorsal, caudal and tail fins. In contrast to the juveniles, adults are very similar to the silver arowana (''O. bicirrhosum''), but the two species can be separated by

meristics Meristics is an area of zoology and botany which relates to counting quantitative features of animals and plants, such as the number of fins or scales in fish. A meristic (countable trait) can be used to describe a particular species, or used to i ...

. Some Asian aquarists occasionally refer to

arowana Arowanas are freshwater bony fish of the subfamily Osteoglossinae, also known as bony tongues (the latter name is now often reserved for Arapaiminae). In this family of fish, the head is bony and the elongated body is covered by large, heavy sca ...

as dragonfish due to their unique appearance and believe they bring good luck.

Behavior

South American arowanas are sometimes called ''water monkey'' or the ''monkey fish'', because they can jump out of the water to capture their

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

. They usually swim near the water surface looking for food. Although it has been known to eat larger prey like small

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s and small monkeys,Mikula, P. 2015: Fish and amphibians as bat predators. European Journal of Ecology 1 (1): 71–80. doi: 10.1515/eje-2015-0010 their main diets consist of shrimps, insects, smaller fishes and other animals that float on the water surface, on which its draw-bridge-like mouth is exclusively adapted for feeding. The females spawn during the high water season. The up to 210 eggs are mouthbrooded by the male and the young only fully released when about long.

References

{{Taxonbar, from=Q916939 Osteoglossidae Fish of the Amazon basin Freshwater fish of Brazil Endemic fish of Brazil Taxa named by Robert H. Kanazawa Fish described in 1966

Etymology

Range and habitat

Description

Behavior

See also

References