Oscar

Grow to about 45 cm (18 in) in length and 1.6 kilograms (3.5 lb) in weight. Max length : 45.7 cm TL male/unsexed; common length : 24.0 cm TL male/unsexed; max. published weight: 1.6 kg

Oscar

In its natural environment, the species typically occurs in slow-moving white-water habitats, and has been observed sheltering under submerged branches. Preferably inhabits quiet shallow waters in mud-bottomed and sand-bottomed canals and ponds. Feeds on small fish, crayfish, worms and insect larvae. Quite popular with aquarists but not for aquaculturists because of its slow growth. Maximum length 40 cm TL. A highly esteemed food fish in South America

The wild-caught forms of the species are typically darkly coloured with yellow-ringed spots or ocelli on the caudal peduncle and on the dorsal fin. These ocelli have been suggested to function to limit fin-nipping by piranha, which co-occur with A. ocellatus in its natural environment. The species is also able to rapidly alter its colouration, a trait which facilitates ritualised territorial and combat behaviours amongst conspecifics. Juvenile oscars have a different colouration from adults, and are striped with white and orange wavy bands and have spotted heads. Since these fish eat fruit in the wild, items such as melons, oranges, and other fruits can also be used as a type of food. Just about anything that falls into the water would be eaten by oscars. Once caught, Captive/ Aquarium oscars may be fed prepared fish food designed for large carnivorous fish: crayfish, worms, and insects (such as flies, crickets and grasshoppers). Feeding live foods may increase the rate of growth but also may cause endoparasites. Dorsal spines (total): 12 - 14; Dorsal soft rays (total): 19-21; Anal spines: 3; Anal soft rays: 15 - 17. Large mouth with thick lips; 7 preopercular pores; first gill arch without lobe; gill rakers short and thick with many denticles; dorsal and anal fins bases densely scaled; many branched rays; body color dark with bright orange opercle margin and ventral parts of the lateral sides of the body; often a black rounded blotch with orange margin at caudal fin base

In captivity, both male and female clean a suitable spawning site - often a flat rock , or branches, or in a circular nest excavated in shallow water. Eggs are deposited and are guarded by both parents. Egg hatch in 3 or 4 days and parent move the fry to a shallow pit in the sand where they remain for 6 or 7 days

Summary of Distribution: South America: Amazon River basin in Peru, Colombia and Brazil; French Guiana. Reported from Argentina. Oscars were introduced to Hawaii and are not a native species.
Note: Distribution range colors indicate degree of suitability of habitat which can be interpreted as probabilities of occurrence (fishbase.org)