Green Terror
Andinoacara rivulatus
Cichlidae
About
The green terror is a robust, iridescent cichlid from the Pacific-slope coastal rivers of western Ecuador and extreme northern Peru, where it patrols small to mid-sized streams over sand and rock. Reaching around 20-25 cm, with dominant males growing larger and developing a pronounced nuchal hump, it is powerful, intelligent and every bit as pugnacious as its name suggests. It digs constantly, rearranges decor and defends a large territory, so it demands careful stocking and a spacious tank.
Care
House a single fish or a bonded pair in a long tank of at least 300 L (150 cm base) with strong filtration, sand substrate and robust rockwork. Keep the water cooler at 20-25 C and expect aggression, so choose only large, equally sturdy tankmates or none at all.
Diet
Opportunistic predator that takes invertebrates and small fish in the wild. Staple on a quality cichlid pellet plus earthworms, prawns, mussel and mysis, with a little vegetable matter; avoid mammalian meats and control portions.
Tankmate compatibility
Possible with care (96)
Avoid (175)
Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.
Telling males from females
What works for this species, most reliable first.
- Extended finsStrong · from about 8 months, and later in a suppressed male
On many cichlids and killifish the male's dorsal and anal fins draw out into trailing points as he matures, while the female's stay rounded.
- VentingA hint only · only on a mature fish, easiest when she is in breeding condition
The method breeders use when the answer has to be right. Hold the fish upside down in a wet hand or soft net and look at the two openings ahead of the anal fin. The forward one is the anus; the one behind it is what you are reading.
- Adult sizeA hint only · only across animals of the same age
In many cichlids, catfish and loaches one sex simply grows larger — usually the male, though there are well-known reversals.
Frequently asked questions
- What tank size does a Green Terror need?
- A Green Terror needs an aquarium of at least 300 litres (79.3 US gallons) with a footprint at least 150 cm (59.1 in) long — for this species, swimming length matters as much as raw volume.
- What water parameters does a Green Terror need?
- Green Terror does best at 20–25 °C (68–77 °F), pH 6.5–8 and a general hardness of 5–25 °dGH.
- Is the Green Terror suitable for beginners?
- Green Terror is a demanding species best attempted with some experience — it needs stable, closely watched conditions to thrive.