robertprice
June 11th, 2013, 10:19 AM
The Oscar, Astronautus ocellatus, is large species found in Peru, Ecaudor Brazil, Colombia, and French Guiana. It is a common food fish of the Amazon. It reaches a length of 18 inches ( usally 12 max in aquariums). It is characterized by a entire body of balck irregular spots and blotches on and orange to orange-red base color, prominent red ringed ocelli on the caudal peduncle and dorsal fin, and an overbite.
There are quite a few color variants, and these have been used by produce Tiger, Red, and Albino Oscars by selective breeding. There are also long-fiined oscars, which really should not be promoted, as the dragging tails decrease the fish's mobility. The ocelli are though to be an adaptation to living with Piranhas to confuse them about where the head is. They live in slow moving backwaters, and are middle of the water column swimmers. The males and females look the same. They are openwater substrate breeders that lay several hundred eggs on flat stones. They are good parents. The young are black and silver.
In captivity they need a 55 gallon tank with strong filtration for a single adult, or a 70 gallon tank for a pair. Single males will fight. They accept a wide variety of water chemistry, pH 6.2 to 7.5, and temperatures from the mid 60's to mid 80's. Because of their hardy water condition tolerances, they have established feral poluations in China, Australia, and the southern United States. They are not picky eaters, and eat a lot, but should not be feed feeder fish as they are prone to catching hole-in-the-head disease (Hexamita). They will eat most meaty foods and pellets.
There is also a smaller species A. crassipinnis, which is predominantly dark brown and white, about 1/3 smaller, and lacks the red ringed tail ocelii. See "Images of Oscars" for pictures.
There are quite a few color variants, and these have been used by produce Tiger, Red, and Albino Oscars by selective breeding. There are also long-fiined oscars, which really should not be promoted, as the dragging tails decrease the fish's mobility. The ocelli are though to be an adaptation to living with Piranhas to confuse them about where the head is. They live in slow moving backwaters, and are middle of the water column swimmers. The males and females look the same. They are openwater substrate breeders that lay several hundred eggs on flat stones. They are good parents. The young are black and silver.
In captivity they need a 55 gallon tank with strong filtration for a single adult, or a 70 gallon tank for a pair. Single males will fight. They accept a wide variety of water chemistry, pH 6.2 to 7.5, and temperatures from the mid 60's to mid 80's. Because of their hardy water condition tolerances, they have established feral poluations in China, Australia, and the southern United States. They are not picky eaters, and eat a lot, but should not be feed feeder fish as they are prone to catching hole-in-the-head disease (Hexamita). They will eat most meaty foods and pellets.
There is also a smaller species A. crassipinnis, which is predominantly dark brown and white, about 1/3 smaller, and lacks the red ringed tail ocelii. See "Images of Oscars" for pictures.