Description

The Threadfin Acara (also known as Acara heckelii, A. subocularis, and Geophagus thayeri) is a striking fish native to the northern Amazon basin in Brazil, Colombia, Guyana, and Peru, with an introduction to Singapore. It can reach up to 23.5 cm (9.3 inches) in size and thrives in warm temperatures ranging from 24-29°C (75-84°F). The species requires soft, slightly acidic water with a pH of 6.0-7.2 and a dH of up to 15 degrees. These fish are best kept in a specialist community, avoiding fin-nipping species. Threadfin Acaras prefer dim to medium lighting, and females are generally fuller-bodied when mature. They are omnivorous, enjoying flakes, granules, cichlid pellets, and frozen foods.

For care, the Threadfin Acara requires a large, biologically mature aquarium (preferably 200 liters or more) with soft sand as substrate for sifting. They need plenty of hiding places, such as driftwood, rocky caves, and plants like Anubias or Java Fern, although plants in the substrate should be avoided as they will be uprooted. Efficient filtration is crucial, with areas of moderate water movement and calm spots for resting. Frequent partial water changes are necessary to maintain optimal water quality. While juveniles and sub-adults are typically peaceful, adults can become territorial, especially when breeding. Keeping them in groups of eight or more juveniles helps establish a natural hierarchy and diffuse aggression. In spacious tanks with sufficient visual barriers, multiple pairs can coexist.

Threadfin Acaras are omnivorous and require a varied diet, including small aquarium flakes, sinking pellets, and frozen foods such as bloodworms, white mosquito larvae, and brine shrimp. Feeding should occur once or twice daily, offering a variety of foods. The breeding behavior of this species is complex, with females digging burrows in the substrate for egg-laying. These burrows often have false entrances to confuse predators. The courtship involves the female soliciting a male, and once they pair, they defend a 2-3 meter territory around the burrow. The female cares for up to 2000 fertilized eggs, while the male patrols the perimeter. Both parents continue to care for the fry until they reach around 12mm in length. Breeding in an aquarium can be challenging due to aggression, but using an upturned flowerpot as a spawning site, adjusting water temperature, and closely monitoring the pair can help trigger successful spawning. It’s important to have a tank divider ready to separate aggressive pairs if necessary.

In conclusion, the Threadfin Acara is a captivating and peaceful fish that is best suited for experienced aquarists. It requires careful attention to water quality, territorial behavior, and breeding management. With ample space, proper care, and patience, these fish can thrive and provide an engaging experience for hobbyists, particularly those interested in breeding.