Intermediate careSemi-aggressiveSchool of 5+North America

Chapultepec Splitfin

Girardinichthys viviparus

The Chapultepec Splitfin (Girardinichthys viviparus) is a semi-aggressive fish that's a good step up once you have a little experience. Give it a tank of at least 75 litres (20 US gallons), water held at 64-75°F, and a pH of 7-8.5. Always keep a group of at least 5 - they feel safest in numbers.

Care levelIntermediate

TemperamentSemi-aggressive

Min tank size19.8 US gal

pH range7-8.5

Temperature64-75°F

Max size2.0 in (5.0 cm)

Captive lifespan2-5 years

SchoolingYes · 5+ recommended

Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.

Natural distribution

North America (Mexico)

Central America & Mexico

Regional colours match the stocking calculator's origin map.

Chapultepec Splitfin Tank Setup

A tank of at least 75 litres (20 US gallons) works well. Keep the water at 64-75°F with a pH around 7-8.5, and set up both cover and open swimming space where they spend most of their time (Mid). Always keep a group of at least 5 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour.

What Do Chapultepec Splitfins Eat?

They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.

Chapultepec Splitfin Tank Mates

Prefers cooler well-oxygenated water The Chapultepec Splitfin is semi-aggressive, which is the first thing to weigh up when you choose tank mates. It's a known fin-nipper, so avoid bettas, guppies, and other slow, long-finned fish. It's a shoaling fish, so settle a group of 5 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.

Are Chapultepec Splitfins Good for Beginners?

Doable once you test water regularly and catch problems before fish look sick. If this is your first tank, pick something more forgiving and come back later.

Chapultepec Splitfin - frequently asked questions

What size tank do Chapultepec Splitfins need?

Chapultepec Splitfins need a tank of at least 75 litres (20 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

How many Chapultepec Splitfins should I keep together?

Keep a group of at least 5. Chapultepec Splitfins are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.

What water parameters do Chapultepec Splitfins need?

Keep them at 64-75°F with a pH of 7-8.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.

What do Chapultepec Splitfins eat?

Chapultepec Splitfins are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.

Are Chapultepec Splitfins good for beginners?

Chapultepec Splitfins are best for keepers with a little experience. They are manageable once you test water regularly and catch problems early; a complete beginner may prefer something more forgiving first.

Common mistakes with Chapultepec Splitfins

Buying fewer than 5 - Chapultepec Splitfins need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.
Mixing with long-finned fish - Chapultepec Splitfins will nip at bettas, angelfish, and other fish with flowing fins, causing stress and infection risk.

Building a community? Run the full list through the stocking calculator before you add anything else.