Fourspotted toothcarp

Phallichthys quadripunctatus

FreshwaterFish

Care at a glance

Temperature: 68–86°F (20–30°C)
pH: 7.0–8.0
Adult size: 1.4 in (3.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Easy
Breeding: Easy
Rarity: Very rare
Origin: Costa Rica
Family: Poeciliidae

Overview

Keep these as a small social group in a tank of about 40 liters or more. They are peaceful mid-water fish that do fine in a community of similarly calm species. Water can run from 20 to 30 C and neutral to slightly alkaline, which makes them forgiving. Feed a varied diet of flake, micro-pellets, and occasional frozen brine shrimp or daphnia. A planted tank with light current keeps them comfortable.

In the wild

This little livebearer comes from slow freshwater streams and rivers in Costa Rica, usually in shallow stretches packed with plants and submerged roots. The water there is warm and runs neutral to slightly hard. Set up a planted tank with gentle flow, some root or wood cover, and a soft substrate. The plants matter both as cover for adults and as hiding spots for fry.

Good to know

Phallichthys quadripunctatus is in the family Poeciliidae, the livebearer group that includes guppies and mollies, and it stays small at around 3.5 cm. Like other poeciliids, it bears live, fully formed young instead of laying eggs, and breeding comes easily. Males have a gonopodium, a modified anal fin used to fertilize females internally. It is not considered threatened, though habitat damage and pollution can affect local populations.

Did you know

Because they breed so readily and the young are born swimming, a stable group will quietly populate a planted tank on its own. The fry hide in the plants and many survive without any extra effort, which makes this a low-fuss species for anyone wanting to watch livebearer behavior over generations.