Astronotus crassipinnis Care Guide
Astronotus crassipinnis is a less common Oscar species from the southern Amazon and Paraná–Paraguay basins, often confused with A. ocellatus.
Compiled by Aquairi from published sources · Published · Updated
Overview
Astronotus crassipinnis is a large cichlid and a less common relative of the familiar Oscar, Astronotus ocellatus. It is generally darker than A. ocellatus and is often mistaken for it in the trade, where it is sometimes called the "fat Oscar". It reaches up to about 25 cm in length.
Taxonomy
- Family: Cichlidae
- Genus: Astronotus
- Scientific name: Astronotus crassipinnis
Habitat
The species occurs in the southern Amazon basin and the Paraná–Paraguay basins of South America, a more southerly distribution than the northern Oscar. As with other Astronotus, it is associated with slow, structured waters.
Tank requirements
- Minimum tank volume: 400 L
- Temperature: 22-28 °C (72-82 °F)
- pH: 6.0-7.5
- GH: 5-18 °dGH
- Lifespan: 10-15 years
- Adult size: up to about 25 cm
Diet
Like other Oscars, Astronotus is a predatory carnivore that takes small fish, shrimp, snails, insects and insect larvae, and also fruits and nuts in the wild. In captivity quality cichlid pellets supplemented with live or frozen items such as earthworms and prawns are appropriate; feeder fish and mammalian or avian meat are best avoided.
Compatibility
Oscars are territorial and defend a claimed area without being exceptionally aggressive for their size. Their predatory nature makes small fish unsuitable as tankmates; robust species of comparable size are preferable, while small tetras, guppies and shrimp should be avoided.
Breeding
Astronotus species are biparental substrate spawners. Pairs clean a flat surface before laying, and both parents guard the eggs and provide extended care to the fry.
Black Oscar (Astronotus crassipinnis) Breeding Guide
Overview
Astronotus crassipinnis is an oscar relative reaching up to about 25 cm, found in the southern Amazon basin and the Paraná-Paraguay basins. It is very rare in the aquarium hobby, where it is sometimes called the "fat oscar". Detailed breeding accounts are scarce, so the reproductive behaviour described here follows the genus Astronotus (the oscar), of which it is a member.
Sexing
Oscars are widely regarded as sexually monomorphic, so external sexing is unreliable; males may grow faster and some strains show dark blotches at the dorsal-fin base. Pairs typically reach sexual maturity around one year of age.
Conditioning
Keep a group of young fish and allow a pair to form, then condition the pair well. In the genus, frequency and timing of spawning may be related to the occurrence of rain, so cooler, softer water changes can help bring fish into condition.
Spawning Behavior & Trigger
Oscars are biparental substrate spawners. A pair selects and cleans a generally flattened horizontal or vertical surface before spawning. Fecundity scales with female size: smaller females lay around 300-500 eggs, while larger females may lay roughly 2,500-3,000.
Egg & Fry Care
Both parents guard the eggs and resulting fry, as is typical of cichlid brood care. As the fry grow they can be moved to and herded around the substrate by the parents until they are free-swimming and feeding.
Common Challenges
Because the species is monomorphic, obtaining a true pair without venting or letting a group pair off is difficult. Its large adult size demands a very large tank, and the rarity of A. crassipinnis means breeding stock is hard to source.