Apistogramma Agassizii Apistogramma agassizii

Quick Stats

Tank Setup

The Apistogramma agassizii is the elegant apisto — longer-bodied and more torpedo-shaped than the deeper-bodied A. cacatuoides, with a pointed face and an extended lyre-shaped tail on mature males. The species comes from soft, acidic blackwater tributaries of the Amazon basin in Peru and Brazil, and captive-bred strains (which is what you are buying) have been line-bred into several stunning colour morphs — most commonly the “double red” (red dorsal and caudal fins) and “triple red” (red dorsal, caudal, and anal fins). A 20 gallon long is the realistic minimum for a harem of one male and two or three females; a 10 gallon works for a single pair but you give up the harem behaviour that makes the species worth keeping.

Maintain water parameters within: temperature 24–28°C, pH 5.0–7.0, hardness 1–8 dGH. That range is slightly tighter and slightly softer than cacatuoides tolerates — agassizii genuinely prefers the acidic end (pH 5.5–6.5) and shows better colour, more spawning, and longer lifespan there. If your tap water is pH 7.5+ and GH 10+ you will need RO water or active substrate (ADA Amazonia) to keep agassizii long-term; cacatuoides will tolerate that water but agassizii will fade, stop breeding, and become disease-prone. I keep my agassizii colony at 26°C, pH 6.0, GH 4 over ADA Amazonia — soft and acidic — and they spawn every 5–7 weeks.

Set up the tank with a fine sand substrate (1–2 mm pool filter sand or play sand, 3–5 cm deep), driftwood, leaf litter (Indian almond leaves), and dense planting along the back and sides. The non-negotiables are caves: one cave per female, plus one spare. Coconut shells with a 1.5 cm entrance hole, half-buried flower pots turned on their side, or slate stacks all work — the entrance must be just large enough for the female to enter and the male to be excluded. Apistogramma are sifters; they will sand-sift all day looking for food, so gravel disqualifies a tank. Add driftwood and leaf litter in the corners to recreate the blackwater look and to provide the tannins that agassizii thrive in.

Tank Mates

Apistogramma agassizii are peaceful for cichlids — until they spawn. A guarding female will attack any fish that comes within a body-length of her cave, including fish three times her size. Plan tank mates around the spawning reality, not the resting state. Compared to cacatuoides, agassizii females are slightly less aggressive defenders; the males are slightly more territorial with each other and with other dwarf cichlids.

Compatible tank mates include: tetras that tolerate 26–28°C and soft acidic water (Ember Tetra, Rummy-nose Tetra, Diamond Tetra, Cardinal Tetra, Neon Tetra), pencil fish (Nannostomus), Corydoras (especially dwarf species like habrosus or pygmaeus), Otocinclus, and peaceful mid-water schooling fish. Avoid housing with other Apistogramma species (they will hybridise or fight), large aggressive cichlids, bottom-dwelling predators like Synodontis catfish, and any fish large enough to eat a 5 cm female. I keep my agassizii with a school of Cardinal Tetras and a group of Corydoras habrosus; the tetras act as dither fish that signal “no predators above”, and the corys occupy the bottom without competing for the caves.

The harem structure matters: one male with two to three females per territory, in a 20 gallon long with broken sight lines. Two males in a 20 gallon will fight — sometimes to death. If you want multiple males, you need a 4-foot tank (40 gallon breeder or larger) with visual barriers between each male's territory. A sexed group of 1M:3F is the standard starter colony; the females will establish a pecking order among themselves, and the dominant female will spawn first. Agassizii males are more elongated and more aggressive toward each other than cacatuoides males — if you keep two males, plan for a larger tank than you would for the equivalent cacatuoides setup.

Diet & Feeding

Apistogramma agassizii are micro-predators. In the wild they eat insect larvae, small crustaceans, and worms pulled from the sand. In the aquarium they accept frozen bloodworm, frozen brine shrimp, live blackworms, live baby brine shrimp, and high-quality micro pellets (I use New Life Spectrum Thera+A 0.5 mm or Fluval Bug Bites Cichlid Mini). Flake is accepted but not ideal — it does not trigger the hunting behaviour that keeps them active and coloured up.

Feed small amounts twice daily. A female guarding eggs or fry will eat very little; do not panic if she refuses food for a week — this is normal. Target-feed with a baster or long tweezers; Apistogramma learn to recognise their keeper and will take food from your fingers within a few weeks. Agassizii are slightly slower feeders than cacatuoides and may be out-competed by fast mid-water fish — if your tetras are eating everything before the apistos get to it, target-feed the apistos directly.

The colour payoff from a varied diet is dramatic. A flake-only agassizii is a brown fish with faint orange trim. The same fish on a frozen-and-live diet for six weeks shows fire-engine red dorsal and caudal fins, a yellow face, and red-and-blue stripes on the ventral fins. The females go from camouflaged grey to electric yellow with black markings the day they start guarding a clutch. The difference between a “double red” and a “triple red” agassizii is genetic, but the intensity of the red in either morph is almost entirely diet-driven. Diet is the single biggest lever on colour in this species.

Common Health Issues

The two conditions I see most in Apistogramma are Hexamita (intestinal flagellates) and bacterial gill disease. Hexamita shows up as white, stringy, buoyant faeces, weight loss despite feeding, and a sunken belly. Treat with metronidazole — either in food (250 mg per 100 g of food for 7 days) or as a bath (500 mg per 10 litres for 7 days, in a separate hospital tank). Bacterial gill disease shows up as rapid breathing, clamped fins, and a fish hanging at the surface; treat with a broad-spectrum antibiotic in a hospital tank and address the underlying water quality. Agassizii are slightly more sensitive to Hexamita than cacatuoides — in my experience the first sign of stress in an agassizii colony is often a Hexamita outbreak.

Ich is a constant threat because Apistogramma tanks run at 26–28°C, the upper end of the ich reproduction range. The standard heat-and-salt treatment is risky: pushing temperature to 30°C to defeat ich will stress your Apistogramma and may trigger bacterial infections. I treat ich in Apistogramma tanks with formalin/malachite green (Rid-Ich or similar) at 75% of the label dose, holding temperature at 28°C. Copper-based treatments are toxic to dwarf cichlids — do not use them.

Prevention is straightforward: weekly 25–30% water changes with dechlorinated, temperature-matched water, no ammonia, no nitrite, nitrate below 20 ppm. Apistogramma tolerate nitrate worse than tetras — a tetra will shrug off 40 ppm nitrate, an agassizii will lose colour, stop breeding, and become disease-prone. Agassizii are particularly sensitive to dissolved organics — if you can smell the tank water, it is too rich for agassizii. Quarantine new fish for four weeks in a hospital tank before adding them to a colony. Lifespan in good conditions is 3–5 years; agassizii tend to the lower end of that range, cacatuoides and borellii to the upper end.

Breeding

Apistogramma agassizii are cave-spawners and one of the easier dwarf cichlids to breed in captivity — though slightly less prolific than cacatuoides. The female initiates spawning: she picks a cave, turns bright yellow with black markings, and leads the male to the entrance. A typical spawn is 40–80 eggs, deposited on the roof or wall of the cave. The male leaves after spawning; the female tends the eggs exclusively. Agassizii spawns are slightly smaller than cacatuoides (40–60 eggs vs 60–80) but the survival rate is comparable.

Eggs hatch in 48–72 hours at 26°C. The female will move the wrigglers to a pre-dug pit in the sand, then to another pit, then another — every 8–12 hours for the first three days. Once the fry are free-swimming (day 5–7 post-hatch), the female herds them around the tank in a tight school, gill-flaring and charging anything that approaches. The male guards the perimeter; in a harem setup, he will rotate between the territories of his females. Agassizii females are slightly more attentive mothers than cacatuoides — they hold the school together longer and are more aggressive in defence.

Feed the fry infusoria for the first three days, then graduate to live baby brine shrimp. They grow quickly on BBS — 1 cm in four weeks, sexable at three months, sexually mature at six months. The most common mistake is feeding flake or pellet too early; Apistogramma fry need live food for the first two weeks or they starve slowly. Females often eat their first clutch — this is normal, and they figure it out by the second or third spawn. A single pair in a 10 gallon species-only tank will produce 20–40 survivors per spawn with no intervention beyond water changes. Breeding for colour morphs is straightforward — double red to double red produces double red; double red to triple red produces a mix, with roughly 50% triple red and 50% double red offspring. Line-breeding for full triple red takes 3–4 generations of culling.

Frequently Asked Questions