Threadfin Acara - Geophagus Heckelli

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