Cascajal toothcarp

Brachyrhaphis cascajalensis

FreshwaterFish

Care at a glance

Temperature: 75–82°F (24–28°C)
pH: 6.5–8.0
Adult size: 3 in (7.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Medium
Breeding: Hard
Rarity: Very rare
Origin: Costa Rica
Family: Poeciliidae

Overview

Keep the cascajal toothcarp in a group with more females than males so that courting males do not wear out any single female. It is an active mid-water fish that is mostly peaceful, though it can nip fins and will snap at very small tankmates, so pick sturdy companions of a similar size. Offer a mixed diet of quality flake, small frozen foods, and let it graze on soft algae and the tiny creatures that grow in a mature tank. It does best in hard, neutral to alkaline water. A tank of 40 liters or larger suits a small group.

In the wild

This species lives in the warm Caribbean-slope streams of Panama and neighbouring Costa Rica, with the Rio Cascajal in Panama giving it its name. It occupies flowing, mineral-rich fresh water and can stray into slightly brackish stretches near the coast. Keep it between 24 and 28 C with a pH from about 6.5 to 8, in clean, well-filtered water with plants and some current. Steady, oxygen-rich conditions matter most.

Good to know

Cascajal toothcarp is a small member of the livebearer family Poeciliidae, described from the Rio Cascajal in Panama. Males reach about 6 cm and females grow a little larger, to around 7.5 cm, and are noticeably deeper-bodied. Males use a gonopodium, a rod-like modified anal fin, to fertilize females internally, and females give birth to live young. Home breeding is possible but less reliable than with common livebearers, so it is best rated as a harder species to raise in numbers.

Did you know

The genus name Brachyrhaphis means short needle, a nod to the compact gonopodium the males use during their quick, darting courtship in fast-flowing water.