TankBud

Threadfin acara

Acarichthys heckelii

Also known as Thread fin acara

FreshwaterFish

Threadfin acara (Acarichthys heckelii)
The original uploader was MidgleyDJ at English Wikipedia. · CC BY-SA 2.5

Care at a glance

Temperature
75–86°F
24–30°C
pH
6.0–7.5
Adult size
7.9 in
20 cm
Minimum tank
79 gal
300 L
Temperament
Mostly peaceful
Social behavior
Social
Swim level
Middle
Difficulty
Difficult
Breeding
Cave spawner · Hard
Rarity
Rare
Family
Cichlidae
Origin
Colombia, Peru, Brazil, Guyana

Overview

The threadfin acara is a medium-sized eartheater for a large tank with plenty of open sand. It is a fish for experienced keepers.

Did you know

In the threadfin acara, it is the female that digs the burrow and does much of the courting. That is the reverse of the usual cichlid arrangement.

Caring for the threadfin acara

A tank of at least 79 gal (300 L) gives a group of threadfin acaras space to sift, swim and sort out territories. A deep bed of fine, soft sand matters most, since it sifts the sand for food and digs into it to breed. Soft sand also protects its mouth. Add driftwood, rocks and the odd cave, and leave open areas of sand for foraging.

Aim for 75 to 86°F (24 to 30°C) and a pH of 6.0 to 7.5. Feed sinking pellets along with frozen and live foods such as bloodworm and brine shrimp.

The threadfin acara does well in a group with room to establish a loose hierarchy. It is mostly peaceful outside of breeding, but it can become territorial and pushy when spawning. It generally coexists with robust, similarly sized tank mates such as larger tetras, other calm cichlids and peaceful catfish.

Its breeding is unusual for a cichlid. A pair spawns in a chamber dug into the sand, reached through one or more long tunnels. The female lays her eggs deep inside and defends the burrow, while the male guards the entrances. Breeding in the aquarium is hard without a deep sand bed and the right conditions to trigger it.

Good to know

The threadfin acara, Acarichthys heckelii, is a member of the cichlid family, Cichlidae. A long, trailing extension of its dorsal fin gives it the name threadfin.

In the wild

The threadfin acara ranges across the Amazon basin through Colombia, Peru, Brazil and Guyana. It lives over sand in slow rivers, lakes and flooded areas. The water there is warm, and it runs from soft and acidic to near neutral.

Weekly picks

Tank mates

The threadfin acara 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 threadfin acara need?

A threadfin acara needs at least 79 gal (300 L). It spends most of its time in the middle.

What temperature and pH does a threadfin acara need?

A threadfin acara is comfortable at 75–86°F (24–30°C) with a pH of 6.0–7.5.

What does a threadfin acara eat?

A threadfin acara eats sinking pellets along with frozen and live foods, such as bloodworm and brine shrimp. It also sifts sand for food.

How big does a threadfin acara get?

An adult threadfin acara reaches about 7.9 in (20 cm).

How does a threadfin acara breed?

Threadfin acaras spawn in a chamber dug into the sand, reached through long tunnels. The female lays her eggs deep inside while the male guards the entrances, and breeding them is hard.

Related species