Oscar Fish in Natural Habitat

The oscar can be observed in its natural habitat in South America.

The oscar, originally described by Louis Agassiz in 1831, in a member of the cichlid family native to the rivers of South America. The oscar is also commonly known as the velvet cichlid, red oscar, tiger oscar and marble cichlid in addition to a number of local names in given to it by the people of South America. In areas where there is a large native oscar population, the fish are commonly sold in meat markets but they have not found popularity in the global market because of slow growth.

Geographical Locations

The oscar is native to the South American regions of Brazil and Peru, specifically in the Rio Ucayali drainage and upper Amazon river. Because of the exotic pet market, nonnative populations have become well established in freshwaters in Australia, Southern Florida and China.

Habitat

Oscars live in freshwater only. They are commonly found in rivers or other white-water areas. They show a marked preference for waters that have little wake, or are slow moving. They also prefer areas with heavy cover, where they can hide and rest, and so seek shelter in sunken trees and dense vegetation. They most often stay near river banks to breed and nest. They are intolerant of cold water, and cannot live in water that falls below 55 degrees.

Diet

Oscars in their natural environment feed largely on smaller fish. They will also eat crayfish, frogs, aquatic insects, insect larva, snails and freshwater clams when available. Though they are often seen as inactive because of their tendency to hide and rest, when hunting they are capable of attacking their prey, moving very rapidly over a short distance in order to capture a fleeing meal.

Physical Description

The lifespan of an oscar left in its native environment is unknown, but in captivity, they typically live between 10 and 20 years. As mature adults, they commonly have girth of up to 2 feet and a length of 18 inches. They may weigh as much as 3 to 3.5 lbs. Oscars have a set of jaw teeth used to grasp food, and a set of throat or pharyngeal teeth are used to chew or manipulate food. Most Oscars are olive green to grey in body color with brown markings. They most distinctive spots are eye shaped and commonly orange in color.

Breeding

Though young males are more colorful than young females, mature male and female oscars have no noticably sex linked characteristics. During the breeding season, oscars are very aggressive and will respond violently to any perceived threat to their spawning site and nest. Male oscars fight over territory and females. When fighting, they will lock jaw teeth, much like deer lock horns. Both the male and the female oscar are actively involved in preparing a nesting and breeding location. They clear off a large flat area, often in sunken logs or on rocks. The female then lays between one and two thousand eggs on the area that was cleared. The development and eventual hatching of eggs is dependent on water temperature.

References

• Vers Aquatics: South American Cichlids
• Florida Museum of Natural History: Oscar