Jeremy Gay tells us about the natural habitat of the Threadfin acara, Acarichthys heckeli. PFK observed and collected this species in the Rio Negro.
Where does it come from?
The Threadfin acara, Acarichthys heckeli, is widespread in the Amazon basin, inhabiting both black and white waters, but we found it in the tannin stained, very soft waters of the Rio Negro, in Brazil. We visited the river at the end of the dry season when it was at its lowest.
Where is it found?
We found A.heckeli in shallow, woody margins of the main river and in permanent pools, cut off apart from occasional flooding. Temperate averaged 28-30°C, with a very low pH. Flow was slow, or still water.
What other fish live alongside it?
In the Rio Negro we found it living alongside Mesonauta insignis, Biotodoma wavrini and Leporinus fasciatus. In the deeper pools it lived alongside angelfish, juvenile Peacock bass, Leporinus, Laemolyta, Satanoperca, Boulengerella and Heros.
How can I breed it?
This species has a very interesting reproductive strategy in the wild as mated pairs dig deep burrows in the vertical mud banks of lakes and rivers, and lay their eggs and protect their fry there.
We saw severums, chocoloate cichlids and festive cichlids also spawning off-bottom, so presumably predation pressures from bottom dwellers are too great to spawn on the river or lake bed. In captivity this species is rarely, if ever spawned and most come in either wild caught or from Singapore, though far eastern origin fish could also be wild.
One strategy I would like to try is to give them a large bucket or plant pot cut into a foam, 3D structured background acting as a false back. Maybe this combined with soft acidic water would do the trick - that or a mud wall!
This item was first published in the November 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.