- Size: Male to 3.5" (9 cm), female to 2" (5 cm)
- Tank: 20 gallons minimum, 24"+ long
- pH: 5.5–7.0
- Temperature: 74–82°F (23–28°C)
- Hardness: Soft, 1–10 dGH
- Temperament: Peaceful toward other species, territorial toward its own
- Difficulty: Intermediate
Overview
Apistogramma agassizii is a widespread South American dwarf cichlid reaching up to 3.5 inches — larger than most apistos — prized for its dozens of regional color forms and identified by a diagnostic black lateral stripe and spade-shaped tail. One of the most widespread Apistogramma species in the wild, found from Peru through Brazil to the Amazon delta — which also makes it one of the most variable. "Agassizii" on a fish tag can mean wildly different things depending on which locality it traces back to: Alenquer red tail, fire red, double red, white seam, and more, each a distinct regional color form rather than a separate species.
What they share is a distinctive spade-shaped caudal fin and a diagnostic black lateral stripe running the length of the body. Males are slender and elongated with intense red, orange, or blue coloration depending on strain, and noticeably longer finnage than females. This is also one of the larger commonly-kept apistos — males can push 3.5 inches, meaningfully bigger than a cacatuoides.
Tank Setup
- Substrate: Fine, smooth sand. Agassizii is a dedicated substrate-sifter and will spend much of its day working through it for food.
- Leaf litter: Recommended, not mandatory — this species ranges across clear-, black-, and whitewater habitats in the wild, so it's more flexible than true blackwater specialists.
- Hardscape: Driftwood, dense planting, floating cover to diffuse light. This species prefers dim, subdued lighting over a bright tank.
- Filtration: Gentle flow — sponge filters or a reduced-flow hang-on-back. Strong current stresses them.
- Tank size: Because of their larger adult size, give a pair more room than you would cacatuoides — 24 inches of length minimum, more for a harem.
Feeding
An unfussy omnivore that takes quality flake, pellet, and live or frozen bloodworms, brine shrimp, and daphnia readily. Live foods bring out the full intensity of red and blue strains in particular. Feed small portions two to three times daily.
Temperament & Compatibility
Peaceful with other species, territorial with its own — the standard apisto pattern, but agassizii's larger size means disputes carry a bit more weight than with cacatuoides or borellii. Best kept as a single male with two or three females rather than a simple pair; that spreads out his attention and reduces the chance any one female gets harassed.
Compatible with tetras, corydoras, and other peaceful community fish that stay out of the bottom territory it claims. As with all apistos, dwarf shrimp are at risk once the fish reach adult size.
Breeding
Conditioning
Condition on live foods for two to three weeks before expecting a spawn. Stable, soft, slightly acidic water helps, though agassizii is more tolerant of parameter drift than blackwater specialists like nijsseni.
Spawning
A cave spawner. The female takes primary responsibility for the eggs, laid on a cave ceiling or wall, while the male defends the surrounding territory from intruders.
Fry Care
Eggs hatch in about 2–3 days, with fry free-swimming within a week. Start on infusoria or crushed fry food, moving up to newly hatched brine shrimp. Keep water quality high — this species does not tolerate elevated nitrates any better than other apistos, regardless of how forgiving it is about hardness.
Variants & Locality Forms
Because agassizii's range is so large, locality and strain matter more here than with most apistos. "Alenquer red tail," "fire red," "double red," and "white seam" are among the more common named forms in the trade — each bred for a specific fin or body color rather than representing a different species. If you plan to breed true to a given form, buy from a source that can tell you the locality or line, and don't mix forms in the same tank.
Where to Get Quality Fish
Given how many color forms circulate under the same species name, ask specifically which strain or locality you're buying — a reputable seller will know. Look for straight spines, undamaged spade tails, and active foraging behavior at the substrate. Visit our sourcing guide for more on vetting sellers.
Final Thoughts
Agassizii rewards keepers who want size and color variety without stepping up to a genuinely difficult blackwater species. It's more tolerant of real-world tap water than nijsseni, more visually varied than borellii, and a natural next step once cacatuoides feels too easy.
Frequently Asked Questions
How big does Apistogramma agassizii get?
Males can reach 3.5 inches, one of the larger commonly-kept apistos, while females stay under 2 inches and are considerably plainer outside of breeding.
What is the minimum tank size for agassizii?
20 gallons minimum, at least 24 inches of length. Because agassizii runs larger than cacatuoides, give a pair more room than you would the smaller species.
Why does agassizii have so many different color forms?
Its wild range stretches from Peru through Brazil to the Amazon delta, so populations vary heavily by locality. Alenquer red tail, fire red, double red, and white seam are among the more common named forms in the trade.
Can agassizii tolerate harder tap water?
More tolerant than blackwater specialists like nijsseni, but breeding is still most reliable in soft, slightly acidic water.
Is agassizii safe with dwarf shrimp?
Not long-term. Adults will eat shrimp fry and small shrimp as they mature, the same pattern seen across most Apistogramma species.
Is agassizii a good second apisto after cacatuoides?
Yes. It offers more size and color variety than cacatuoides without stepping up to a demanding blackwater specialist, making it a natural next species.
Apistogrammarama is written and maintained by the aquarium staff at Pet Zone Tropical Fish in San Diego, who have imported and kept South American dwarf cichlids since the store's founding in 2007.