TankBud

Sailfin tetra

Crenuchus spilurus

Also known as Sailfin characin

FreshwaterFish

Sailfin tetra (Crenuchus spilurus)
The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature
73–82°F
23–28°C
pH
5.0–6.5
Adult size
2.4 in
6 cm
Minimum tank
20 gal
75 L
Temperament
Mostly peaceful
Social behavior
Social
Swim level
Middle
Diet
Carnivore
Difficulty
Medium
Breeding
Medium
Rarity
Common
Family
Crenuchidae
Origin
Northern South America: Amazon and Orinoco basins plus coastal rivers of the Guianas (Guyana, Suriname, French Guiana)

Overview

The sailfin tetra is a small, shy fish for the middle of a dim, mature blackwater tank. It is better suited to a keeper with some experience than to a beginner.

Did you know

When two male sailfin tetras face off over a patch of territory, they spread their sails at each other and lock jaws. The jaw lock is a short shoving match, and neither fish takes real damage.

Caring for the sailfin tetra

Keep sailfin tetras in a mature, dimly lit tank of at least 20 gal (75 L). Give them sand, plenty of driftwood and a layer of dried leaves on the bottom. They hover in open water among roots and leaf litter, in the middle of the tank. They are sensitive to organic waste, so keep the tank well established and the water quality good.

The water should run warm, soft and acidic, at 73 to 82°F (23 to 28°C) and a pH of 5.0 to 6.5. The sailfin tetra is a micropredator and often refuses dry food. Feed small live or frozen foods such as baby brine shrimp, daphnia, moina, and grindal worms or microworms.

Keep a small group of about six with more females than males, or just a pair. They live in loose groups rather than tight schools, and males set up small territories, so extra females cut down on sparring. They are mostly peaceful but timid, so choose calm tank mates of similar size. Skip nano fish, fry and dwarf shrimp, which they will eat.

Males have a tall, flowing dorsal fin they flare during displays, and females stay plainer, with shorter fins. Sailfin tetras spawn in caves and on the substrate, and the male guards the eggs. The eggs hatch in roughly 36 to 48 hours, and the fry are free swimming after another four to six days.

Good to know

Despite the name, the sailfin tetra is not a true tetra. It sits in the family Crenuchidae, the South American darters. Some fish from the northern part of its range reach about 7 cm.

In the wild

Sailfin tetras come from blackwater in northern South America, across the Amazon and Orinoco basins and the coastal rivers of the Guianas. These are dim, slow, soft and acidic stretches, stained brown with tannins from leaf litter and fallen wood.

Weekly picks

Tank mates

The sailfin tetra is a mostly peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a sailfin tetra need?

A sailfin tetra needs at least 20 gal (75 L). It spends most of its time in the middle.

What temperature and pH does a sailfin tetra need?

A sailfin tetra is comfortable at 73–82°F (23–28°C) with a pH of 5.0–6.5.

What does a sailfin tetra eat?

A sailfin tetra is a micropredator and often refuses dry food. Feed it small live or frozen foods such as baby brine shrimp, daphnia, moina, and grindal worms or microworms.

How big does a sailfin tetra get?

An adult sailfin tetra reaches about 2.4 in (6 cm).

How can you tell a male sailfin tetra from a female?

Males have a tall, flowing dorsal fin they flare during displays. Females stay plainer, with shorter fins.

How does a sailfin tetra breed?

Sailfin tetras spawn in caves and on the substrate, and the male guards the eggs. The eggs hatch in roughly 36 to 48 hours, and the fry are free swimming four to six days later.

Related species