Sicklefin livebearer

Girardinus falcatus

Also known as Goldbelly topminnow, Golden girardinus

FreshwaterFish

Care at a glance

Temperature: 68–82°F (20–28°C)
pH: 7.0–8.0
Adult size: 2.6 in (6.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Top
Difficulty: Easy
Breeding: Easy
Rarity: Rare
Origin: Endemic to Cuba, in ponds, lakes, ditches, and slow lowland streams with hard water.
Family: Poeciliidae

Overview

Keep six or more in 40 liters or larger at 20 to 28 C, pH 7.0 to 8.0, in medium hard to hard water. Feed a varied diet of flake, small frozen foods, and some algae or vegetable matter. Generally peaceful, though it will nip long fins and eat very small fry, so choose tankmates accordingly. An easy, forgiving fish that suits a hard water community.

In the wild

A slim Cuban topminnow with a metallic gold belly stripe and, in males, a distinctive curved gonopodium that gives the sicklefin name. It hangs near the surface in loose groups and darts for food. Keep a group in a planted tank with hard water and some open surface space. It grazes algae and small invertebrates.

Good to know

Girardinus falcatus is a Cuban livebearer whose males have a strongly curved, sickle shaped gonopodium used to fertilize females. Females reach about 6 cm and males stay smaller at around 4 cm. It is hardy and breeds freely, which makes it a good starting point for keepers new to wild livebearers.

Did you know

The sickle shaped gonopodium of the male is so distinctive that it gives the fish both its scientific name falcatus, meaning sickle shaped, and its common name.