Acarichthys heckelii, or Threadfin Acara, is one of the more elegant-looking cichlids, developing long trailing thread-like projections on their dorsal fin as adults. These fish are native to the northern parts of the Amazon basin in Colombia, Peru, and Brazil. Adults can reach up to 8 inches in length and require a large aquarium (minimum of 55 gallons, but larger being preferred). A. heckelii are relentless diggers and do best with fine sand substrate. These fish can be very sensitive to poor water quality and any rapid changes in water chemistry so larger volume setups with high filtration are recommended to maintain stable parameters. Optimal water temperature is between 78 and 86 degrees Fahrenheit and with a pH of 6.0 to 8.0. A. heckelii are relatively peaceful and do well in a community of other peaceful fish comparable in size. Sexually mature adults (2-3 years old) may exhibit unpredictable aggression towards conspecifics, but larger aquariums and group sizes help decrease the chance of this aggression. Like many other cichlids, A. heckelii are omnivores and will accept a wide variety of dry food but should be offered live or frozen foods to ensure proper nutrition. These fish dig through the substrate to find food so be sure to choose food like sinking pellets or burrowing black worms. In the wild, these fish exhibit very interesting spawning behaviors. The females will dig an elaborate nest in the sand with multiple entrances (and even false entrances) connecting to a tunnel where the female will care for her eggs as the male guards the nest.
Photo credit: Fishbase.org Nilsson K.
Ask your local independent pet store if they carry beneficial wild-caught Rio Negro Fish; they are a challenge to find because of seasonality and other challenges. The purchase of these fish from sustainable wild-caught sources helps drive environmental conservation and stewardship in the Rio Negro area of Brazil providing livelihoods and protecting the rainforest from destruction – “Buy a Fish, Save a Tree”.
Do you know there are hundreds of species of aquarium fish wild-caught collected in the Rio Negro Fishery of Brazil? We are spotlighting a few of the species this season to raise awareness about the variety of species from the Rio Negro as part of our mission to study and foster this beneficial fishery.