Astronotus ocellatus is a species of fish from the cichlid family, originally described by Louis Agassiz in , although he mistakenly classified it in the marine. Oscars, Astronotus ocellatus, are freshwater fish found in areas with warm water temperatures. Oscars are native to South America, throughout the Amazon and. Oscar. Oscar. Photo courtesy U.S. Geological Survey/Howard Jelks. Astronotus ocellatus. These fresh water cichlids prefer slow-moving water.

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These fresh water cichlids prefer slow-moving water with sunken branches and logs to hide behind. These stocky, oval fish form breeding pairs to tend to and aggressively defend their offspring. The oscar is one of the many cichlids popular in the aquarium trade, often bred and cross-bred to create unusual varieties. Common Qstronotus names include oscarvelvet cichlid, red oscar, tiger oscar, and marble cichlid.

Astronorus oscar is a very popular aquarium fish in North America and Europe. The breeding populations of oscars established in areas of South Florida stem from a deliberate stocking event in Dade county by aquarium fish farms in the late s.

The many interconnected canals of South Astronotks along with transportation by individual anglers to new areas has aided the dispersal of this introduced species. Established in no less ocellatys 6 counties, the oscar is one of the few exotic fishes reproducing in the marginalized habitats of South Florida to have obtained a foothold in Everglades National Park.

The direct effect of the oscar on native species or the ecological balance of the park is unknown, but owing to the fact that native sunfishes in the region possess similar habits and ecological needs to that of the oscar, there is concern regarding the potential for harm. Dispersal northward in Florida appears to be restricted by temperature. A Florida Game and Freshwater Fish Commission study determined the mean lower lethal temperature for this species is In its native range, the oscar is valued by artisanal fishers as a food fish.

The IUCN is a global union of states, governmental agencies, and non-governmental organizations in a partnership that assesses the conservation status of species.

The error committed by Agassiz is easily attributable to the fact that many early species descriptions were based on specimens shipped to zoologists from far-flung locales and often these specimens were accompanied by little in the way of specific locality data. Indeed, there are many instances of early species descriptions with locality errors astronogus to the case of the oscar. Oscars show a preference for slow moving waters that afford them cover in the form of sunken branches and logs.


Captive oscars are commonly observed to rest on the substrate at night. Distinctive Features The oscar is a large, somewhat stocky cichlid with an oval shaped body, a large head, large eyes, and a large mouth. The first dorsal fin is spinous; the second is composed of soft rays and has a rounded shape.

The anal fin is spinous anteriorly and also possesses a rounded edge.

Human uses

Both the base of the soft dorsal and anal fins are scaled. Coloration Oscars are olive-green to gray to chocolate brown in base color with a mottling of some or all astronotys these colors.

A large black spot surrounded by an orange ring present on either side of the base of the upper caudal peduncle is a striking characteristic of this species. Oscars appear to suffer less injury from fin-nipping piranhas than do astronotsu similar cichlid fishes lacking eyespots and living within the same range.

Eyespots or disruptive coloration associated with the actual eyes are fairly common traits amongst fishes, and such characteristics have independently evolved along many separate evolutionary lines. Additionally, more than one study has determined that the eyespots of oscars serve as important cues in intraspecific communication, particularly during courtship and agonistic displays.

A number of artificially selected aquarium color varieties exist including an albino morph among others.

Oscar (fish) – Wikipedia

Individuals with greatly elongated fins have also been produced for the aquarium hobby. Juveniles are strikingly marked fishes characterized by a series of prominent wavy white and orange bars and numerous small white spots randomly distributed on the head. Dentition Like all cichlids, oscars possess teeth not only in their jaws but a set of pharyngeal teeth as well.

Teeth in the jaws are small and used for grasping while those in the throat the pharyngeal teeth manipulate and process prey items. The type and arrangement of teeth on the pharyngeal jaw plates are one of many important characters useful to systematists in deciphering the evolutionary relationships of cichlids and much study on this important feature has been published.

Size, Age, and Growth Captive oscars commonly live years. The oscar is a large cichlid reaching lengths of 33cm and a maximum weight of approximately 1. Food Habits The natural diet of oscars consists largely of smaller fishes, crustaceans, gastropods, and aquatic insects or insect larvae. Although oscars are generally sluggish or inactive, they are capable of ambushing and capturing fleeing prey over short distances. Oscars in captivity exhibit voracious, somewhat indiscriminate feeding habits.

Reproduction No well defined external differences are discernable for male and female oscars although males tend to astronottus larger and more colorful. Breeding oscars defend their spawning sites, nest, and young quite fiercely.


Male oscars may lock jaws in disputes over territory or mate selection. In captivity male and female have been observed to jointly prepare the breeding site. Eggs are adhesive and laid on a flat open surface cleared by the breeding pair. Hatching of eggs is temperature dependent, but typically occurs within 3 to 4 days.

A single spawning may consist of as many as — eggs. Like most cichlids, oscars tend and guard their young.

ADW: Astronotus ocellatus: INFORMATION

Non-native populations in South Florida are observed to spawn primarily during summer months. Predators Oscars rely on their cryptic coloration and eyespots to elude or confuse predators. Generally sluggish, oscars are capable of swimming away quite rapidly over short distances. Nonetheless, all age classes of oscars are susceptible to a suite of predators including invertebrates, fishes, wading birds and reptiles.

Little is known regarding the parasites and diseases of wild oscars. The genus Lobotes however, is entirely marine, and fishes of this genus, known as tripletails Lobotidae are of no meaningful relation to cichlids.

It is surmised that Agassiz chose Lobotes in describing the oscar based on the fact that he believed his specimen or specimens to have been collected in the Atlantic Ocean.

Considering the similarity in appearance of the oscar to the marine tripletails and the erroneous locality information, the original placement of the oscar in Lobotes is not surprising. Current taxonomic placement of the oscar is in the South American cichlid genus Astronotus. Ocellatus is Latin for spotted, referring to the spotted pattern on the body of this fish.

Oscar (fish)

Synonyms astronotis Acara compressus Cope and Hyposticta acara Cope Astronotus ocellatus as originally described appears to be restricted to Peru and Brazil. Discover Fishes Astronotus ocellatus. Importance to Humans Oscars spend time resting under cover. Danger to Humans The oscar poses no danger to humans. Habitat Oscars show a preference for slow moving waters that afford them cover in the form of sunken branches and logs.

Biology Oscar showing coloration patterns, including the characteristic orange ring on the base of the caudal peduncle. Oscars prey upon crayfish. Photo courtesy National Park Service Food Habits The natural diet of oscars consists largely of smaller fishes, crustaceans, gastropods, and aquatic insects or insect larvae.