Astronotus crassipinnis

Astronotus crassipinnis is native to the Paraguay River system and the Pantanal wetlands, where it inhabits warm, slow-moving, often turbid waters. It closely resembles A. ocellatus in behaviour and appearance but remains smaller, making it a more practical option for hobbyists without room for the full-sized Oscar. It shares the same bold, inquisitive personality, quickly recognising its keeper and responding to feeding time. The species is adaptable regarding water chemistry but benefits from warm temperatures and excellent filtration given its messy feeding habits.

Water: 22–28°C, pH 6.0–7.5, soft to moderately hard (GH 5–18). Tank: Minimum 300L; robust décor only as Oscars rearrange everything; strong filtration essential. Feeding: Carnivore; large cichlid pellets, frozen prawn, earthworms, mussel; avoid feeder fish. Breeding: Open substrate spawner on flat rock; prolific parents; brood sizes similar to A. ocellatus. Compatibility: Keep with similarly sized robust cichlids or alone; eats smaller fish.