Dwarf merry widow

Phallichthys tico

Also known as Tico livebearer

FreshwaterFish

Dwarf merry widow (Phallichthys tico) — Livebearerguy · CC BY-SA 4.0

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 6.5–7.8
Adult size: 1.4 in (3.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Medium
Breeding: Easy
Rarity: Rare
Origin: San Juan drainage, Costa Rica and Nicaragua
Family: Poeciliidae

Overview

This is one of the smallest livebearers, a gentle nano-sized fish best kept as a colony of several, with females outnumbering males. It occupies the middle of the tank and appreciates plenty of soft plant cover to weave through. It is thoroughly peaceful and easily bullied or outcompeted, so keep it only with tiny, calm tankmates or on its own in a planted species tank. Feed small foods it can actually manage: crushed flake, micro pellets, baby brine shrimp, and some soft green matter, since it grazes plants in the wild. A modest 40 liter planted tank suits a breeding group.

In the wild

In the wild the dwarf merry widow lives along the San Juan drainage of Costa Rica and Nicaragua, in warm, still or slow water at the margins of streams and ponds, usually among dense aquatic plants. Match that with a warmly heated, gently filtered tank, 22 to 27 degrees Celsius and pH around 6.5 to 7.8, thick planting, and a dark substrate. Floating plants to soften the light help it feel secure and show its colors.

Good to know

Phallichthys tico is a small poeciliid livebearer described by William Bussing in 1963, reaching only about 3.5 centimeters, with females larger than the slender males. It is a superfetating species, meaning a female can carry several broods at different stages of development at once and release young in overlapping batches. Breeding is easy; the main task is keeping fry safe among plants.

Did you know

The species name tico is the affectionate word Costa Ricans use for themselves, so the fish is in effect named after the people of the country it comes from. It is also among the tiniest livebearers kept in the hobby.