Photo: (c) Andrew Durso, some rights reserved (CC BY) — via iNaturalist
Ocellaris Peacock Bass (Cichla ocellaris)
A jewel-marked apex predator for the dedicated large-cichlid keeper — striking colour, explosive feeding strikes and near-zero tolerance for small tank-mates.
Will it live with a Ocellaris Peacock Bass?
We compare each fish against your ocellaris peacock bass on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Black Doras Catfish✅ CompatiblePeaceful · 60 cm · Hard care · 22–28 °C (72–82 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Common Pleco✅ CompatiblePeaceful · 45 cm · Medium care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Sailfin Pleco✅ CompatiblePeaceful · 50 cm · Medium care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Yellow-spotted Pleco✅ CompatiblePeaceful · 35 cm · Medium care · 24–27 °C (75–81 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
- Bearded Corydoras⚠️ With cautionPeaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
- Ocellaris Peacock Bass may bully the smaller Bearded Corydoras, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Bristlenose Pleco⚠️ With cautionPeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Ocellaris Peacock Bass may bully the smaller Bristlenose Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Clown Loach⚠️ With cautionPeaceful · 30 cm · Medium care · 25–30 °C (77–86 °F)
- Ocellaris Peacock Bass may hunt Clown Loach, fry or shrimplets — safest in a heavily planted tank.
- Clown Pleco⚠️ With cautionPeaceful · 9 cm · Medium care · 24–28 °C (75–82 °F)
- Ocellaris Peacock Bass may bully the smaller Clown Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Elephant-nose Knifefish⚠️ With cautionPeaceful · 35 cm · Hard care · 24–29 °C (75–84 °F)
- Watch for Ocellaris Peacock Bass picking off any elephant-nose knifefish small enough to fit in its mouth.
- Giant Glass Catfish⚠️ With cautionPeaceful · 15 cm · Medium care · 22–27 °C (72–81 °F)
- Ocellaris Peacock Bass is aggressive and may chase or nip the smaller Giant Glass Catfish — plant heavily and break up sight lines.
- Ocellaris Peacock Bass may bully the smaller Giant Glass Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Koi⚠️ With cautionPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Your 750 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Marbled Hoplo⚠️ With cautionPeaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Ocellaris Peacock Bass may bully the smaller Marbled Hoplo, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Medusa Pleco⚠️ With cautionPeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Ocellaris Peacock Bass may bully the smaller Medusa Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Porthole Catfish⚠️ With cautionPeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Ocellaris Peacock Bass may bully the smaller Porthole Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Rubber Lip Pleco⚠️ With cautionPeaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
- Ocellaris Peacock Bass may bully the smaller Rubber Lip Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Snowball Pleco⚠️ With cautionPeaceful · 16 cm · Medium care · 24–30 °C (75–86 °F)
- Ocellaris Peacock Bass may bully the smaller Snowball Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Spotted Rubbernose Pleco⚠️ With cautionPeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Ocellaris Peacock Bass may bully the smaller Spotted Rubbernose Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Spotted Talking Catfish⚠️ With cautionPeaceful · 15 cm · Easy care · 22–26 °C (72–79 °F)
- Ocellaris Peacock Bass may bully the smaller Spotted Talking Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Upside-down Catfish⚠️ With cautionPeaceful · 10 cm · Easy care · 22–26 °C (72–79 °F)
- Ocellaris Peacock Bass may bully the smaller Upside-down Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Zebra Pleco⚠️ With cautionPeaceful · 10 cm · Hard care · 26–30 °C (79–86 °F)
- Ocellaris Peacock Bass may bully the smaller Zebra Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Two assertive fish, one genuinely aggressive: Ocellaris Peacock Bass and Alligator Gar will hold territory and clash.
- Size gap is too large (250 vs 70 cm): Alligator Gar will treat Ocellaris Peacock Bass as food.
- Your 750 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Ocellaris Peacock Bass and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Ocellaris Peacock Bass and Fire Eel are both territorial and at least one is outright aggressive — expect serious fighting.
- Mekong Giant Catfish⛔ Not recommendedSemi-aggressive · 300 cm · Hard care · 20–28 °C (68–82 °F)
- Two assertive fish, one genuinely aggressive: Ocellaris Peacock Bass and Mekong Giant Catfish will hold territory and clash.
- Your 750 L tank is below the ~100000 L this pairing really wants — crowding raises aggression.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Two assertive fish, one genuinely aggressive: Ocellaris Peacock Bass and Redtail Catfish will hold territory and clash.
- Redtail Catfish may hunt Ocellaris Peacock Bass, fry or shrimplets — safest in a heavily planted tank.
- Your 750 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Two assertive fish, one genuinely aggressive: Ocellaris Peacock Bass and Spotted Gar will hold territory and clash.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Two assertive fish, one genuinely aggressive: Ocellaris Peacock Bass and Wels Catfish will hold territory and clash.
- Wels Catfish (300 cm) is big enough to swallow the 70 cm Ocellaris Peacock Bass whole.
- Your 750 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Ocellaris Peacock Bass and Wolf Cichlid are both territorial and at least one is outright aggressive — expect serious fighting.
- Your 750 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Ocellaris Peacock Bass care specs
- Care level
- Hard
- Breeding
- Hard
- Max size
- 70 cm (27.6 in)
- Min tank size
- 750 L (198.2 gal)
- Temperature
- 24–30 °C (75–86 °F)
- pH
- 6.5–7.5
- Hardness
- 2–12 dGH
- Lifespan
- 8–15 years
- Diet
- Carnivore
- Swim level
- Middle
- Group size
- Best alone or in a pair
- Family
- Cichlidae
- Origin
- South America — Amazon and Orinoco river basins (Brazil, Venezuela, Guyana)
What is an Ocellaris Peacock Bass?
The Ocellaris Peacock Bass (Cichla ocellaris) is one of the largest and most visually commanding cichlids in the freshwater hobby. Native to the Amazon and Orinoco river basins — Brazil, Venezuela and Guyana — wild specimens reach 70 cm (28 in); aquarium fish commonly top out at 40–55 cm (16–22 in), enough to dwarf virtually every tank companion.
The common name references the bold ocellus — a ringed, eye-like spot — on the caudal peduncle. Paired with golden-yellow flanks and three dark lateral blotches, it gives the species an almost painted appearance that intensifies during breeding condition. Despite the name, peacock bass are true cichlids, sharing the same territorial intensity as oscars and large South American relatives.
This is a specialist fish. Adult size, extreme aggression, high bioload and exacting water requirements combine to make it unsuitable for beginners — but for experienced keepers with the space, few freshwater species are as visually rewarding.
Where does the Ocellaris Peacock Bass come from?
Wild Cichla ocellaris inhabit the large, warm river systems of northern South America — principally the Amazon basin and the Orinoco drainage in Venezuela. They occupy open water: large rivers, flooded savannahs and reservoir margins, hunting by sight in clear or lightly stained water. In their native habitat water is warm (24–30 °C / 75–86 °F), soft to moderately hard (2–12 dGH) and slightly acidic to neutral (pH 6.5–7.5). Seasonal water-level swings trigger breeding behaviour. The species has also been introduced via sport fishing into Florida, Hawaii and Panama, where it has proven highly invasive.
Understanding this open-water origin shapes every husbandry decision: this is not a planted-tank fish, not a cave fish, and not a species suited to cramped quarters.
What tank setup and size does an Ocellaris Peacock Bass need?
The minimum for a single adult is 750 litres (200 gallons) — and that is genuinely the floor. A long footprint of at least 200 cm (6.5 ft) matters more than raw volume; peacock bass are built for explosive straight-line acceleration and a tall, narrow tank of the same litreage is functionally inadequate. A bonded pair will need considerably more; many serious keepers move adults into custom indoor ponds of 2,000 L (500 gal) or more.
Decor should be sparse: one or two large pieces of driftwood or rock to define territory, with the majority of the mid-column left open. Dense planting is impractical given the fish’s size and activity.
Filtration must be oversized — dual canister filters or a sump rated well beyond the tank volume are standard practice. Target 8–10x turnover per hour. Weekly water changes of 30–40 % are non-negotiable; nitrate accumulation directly suppresses appetite and immune function in this species.
What water parameters does an Ocellaris Peacock Bass need?
- Temperature: 24–30 °C (75–86 °F). Temperatures below 22 °C suppress immunity and feeding; the species is not cold-tolerant.
- pH: 6.5–7.5 — slightly acidic to neutral.
- Hardness: 2–12 dGH. Very hard tap water should be cut with RO.
- Ammonia / Nitrite: Zero at all times.
- Nitrate: Below 20 ppm via regular water changes.
Stability matters as much as hitting target numbers. Rapid swings — especially temperature drops — can trigger lateral line disease. Use a reliable heater and a separate thermometer to cross-check on a tank this size.
What do Ocellaris Peacock Bass eat?
Ocellaris Peacock Bass are obligate carnivores. Juveniles can be started on frozen feeder fish, large earthworms and cut fish flesh to establish a feeding response, but the long-term goal is transitioning adults to quality prepared foods — large cichlid pellets, frozen silversides and whole prawns. Feeder fish (especially goldfish) carry significant disease risk and are best avoided as a dietary staple.
Feed adults every one to two days. Overfeeding amplifies the already high ammonia load, and a peacock bass refusing food for a day or two after a large meal is perfectly normal — they are feast-or-famine hunters. Prolonged refusal (two weeks or more) with visible weight loss warrants investigation into water quality or disease.
How does the Ocellaris Peacock Bass behave, and what are compatible tank-mates?
This species is highly aggressive and is best treated as solitary or species-only. Any tank inhabitant that fits in the mouth — which, at adult sizes of 40–70 cm (16–28 in), includes most freshwater fish — will be eaten.
Viable companions are limited to fish too large to swallow and robust enough to survive territorial confrontations: very large arowana, large bichirs (Polypterus spp.), big plecostomus, and sizable cichlids of comparable mass. Even these combinations require a generously sized tank and carry no guarantee of long-term peace. A bonded pair can work if raised together from juveniles, but two males without enough territory will fight destructively.
For a species-by-species breakdown see Ocellaris Peacock Bass tank mates.
How do you tell male and female Ocellaris Peacock Bass apart?
Sexual dimorphism becomes clear as fish approach breeding maturity. Males develop a prominent nuchal hump — a fatty, rounded forehead protrusion — that is absent or much reduced in females. The hump is most pronounced during spawning season and may partially regress between cycles. Females are generally smaller and lack the hump; outside of breeding condition, sexing young adults can be difficult, as both sexes share the same colour pattern. Males tend to be stockier overall.
Can you breed Ocellaris Peacock Bass in captivity?
Captive breeding is possible but rated hard, and rarely achieved in standard home aquaria. It is most likely in very large tanks or indoor ponds where a bonded pair has established stable territory.
Conditioning involves raising temperature toward 28–30 °C (82–86 °F), increasing water-change frequency to simulate seasonal influx, and providing a flat, smooth spawning surface — a large flat rock or a cleaned patch of substrate. Peacock bass are substrate spawners: the female deposits hundreds to over a thousand eggs on the surface and both parents guard aggressively, requiring full separation of all other inhabitants. Fry are large enough at free-swimming stage to take baby brine shrimp; they grow quickly. The main challenge is not hatching the eggs but managing parental aggression and raising large numbers of fast-growing carnivorous juveniles.
What diseases commonly affect Ocellaris Peacock Bass?
The most common health issues in captive peacock bass are directly linked to husbandry failures rather than species-specific vulnerabilities.
Hole-in-the-Head (HITH) / Head and Lateral Line Erosion (HLLE) — pitting lesions around the head’s sensory pores and lateral line — is one of the most common large-cichlid conditions. Poor filtration, elevated nitrates and dietary gaps are the primary causes; excellent water quality and a varied diet are the best prevention.
Ich (Ichthyophthirius multifiliis) presents as white salt-grain spots and is typically introduced via new fish or live food. A strict quarantine protocol for anything entering the tank is essential.
Bacterial infections (open sores, fin erosion, cloudy eyes) most often follow physical injury from aggression or chronic poor water quality. Intestinal parasites can enter via feeder fish; sourcing prepared and frozen foods reduces this risk considerably.
Health note: disease identification and medication dosing are beyond the scope of a care profile. If your fish shows persistent symptoms, consult a veterinarian with aquatic experience or a reputable fish-health reference before treating. Always address water quality first — the majority of large-cichlid health problems clear when husbandry is corrected.
How long does an Ocellaris Peacock Bass live?
A well-kept Ocellaris Peacock Bass lives 8–15 years. Reaching the upper end requires consistent commitment: large, stable, clean water, a varied diet and sufficient space to avoid chronic stress. Growth is rapid in the first two to three years — juveniles can reach 30–40 cm (12–16 in) quickly — then slows considerably. The small fish you buy at 8 cm (3 in) may share your home for well over a decade; budget the space, filtration and running costs before purchasing.
Frequently asked questions
Can I keep an Ocellaris Peacock Bass with other fish?
Only with fish too large to be eaten — think arowana, large stingrays, bichirs or other sizable cichlids. Any fish that fits in its mouth will be swallowed. Even comparably sized tank-mates risk injury from territorial disputes, so species selection must be chosen with care.
How large a tank does a Peacock Bass actually need?
At full size (up to 70 cm / 28 in), a pair requires an indoor pond or a tank of at least 750 litres (200 gallons) with a long footprint. Juveniles sold at 5–10 cm grow rapidly and outgrow standard aquariums within a year — plan for the adult size before purchasing.
What you need to keep a ocellaris peacock bass
The baseline is a heated, filtered 750 L+ tank: a reliable heater to hold 24–30 °C (75–86 °F), a gentle filter that won't batter a ocellaris peacock bass in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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