Family: Cichlidae
A large, intelligent Amazonian cichlid and classic 'wet pet'. Needs a very large tank; territorial.
A Cichlidae species native to South America (Amazon basin): Astronotus ocellatus lives mid-water swimmer over clear streams, rivers and still waters. Semi-aggressive; intelligent and territorial. Adults reach 32–45.7 cm.
32–45 cm in captivity — a giant among mid-sized cichlids, living 10–15 years. Think before buying: this is a one-fish-for-the-whole-tank commitment. Cute juveniles don't stay small; big fish in small tanks is the classic mistake.
457 L (about a 120 cm tank) minimum for an adult, more is better. They're heavy waste producers, so run filtration at 3–5 tank volumes per hour. Many keepers start juveniles in 60 cm tanks — a year later the 30 cm fish has nowhere to go.
Yes. They're among the most intelligent cichlids — they learn who feeds them, swim up begging when you approach, and some tolerate being petted. That interactivity is exactly why they never go out of style in the Chinese hobby.
Carnivores that eat almost anything: pellets, bloodworms, small fish, shrimp, earthworms. But they never feel full — obesity is common. Skip one feeding day a week and give adults only until they're 80% full; excess fat shortens lifespan and compresses organs.
Adults are strongly territorial — only pair them with equally large, equally assertive fish: parrot cichlids, large cichlids, arowanas (in big tanks). Gentle tankmates just become snacks. There's a brief juvenile community window; adults are best kept singly.
Rooting through sand is natural foraging behavior — any substrate becomes hills and valleys. Go bare-bottom or a thin fine-sand layer, and weight the hardscape well; it can shift decor with its mouth. Plants won't survive — it eats or uproots them.
Don't panic — laziness is their nature, and lounging after a meal is normal. Worry only if lying flat comes with refused food, rapid breathing or a darkened body; that's a water-quality or illness signal. The test is simple: excited at feeding means lazy, no appetite means sick.
Often the first surface sign of hole-in-the-head (Hexamita) or ich. Untreated, hole-in-the-head literally perforates the head — treat with metronidazole plus vitamin-rich foods. Clean water and dietary variety are the best prevention.
22–25 °C is ideal. They handle cool water surprisingly well, tolerating 18 °C unheated through winter, but chronic chill weakens immunity. Don't hold them above 28 °C long-term — high temperature plus a big fish equals oxygen risk.
Three: small tank for a fast-growing fish (it triples in a year), insufficient filtration (it's a waste machine — pack the media), and wrong tankmates (it's not a bully; it just sees every gentle fish as food).