Rights: The University of Waikato Published 20 November 2007 Download

Peter Cattin from Auckland University explains what they need in order to effectively look after their zebrafish.


Peter Cattin (Auckland University): The fish like a temperature of around about 25 – 28 degrees [Celsius]. They are a tropical fish. They come from the Ganges River in India, so they wouldn’t survive in our local fresh water rivers. We have to try and approximate the conditions that they thrive in.

It simply requires an aquarium and a heater and a filter system. In fact, most people can over-science things and end up with more difficulties than by keeping it simple. The fish simply want clean water and small amounts of feed regularly. You would need a breeding trap to contain the breeding fish to prevent the adults from cannibalising the young. But it’s all stuff that is readily available and relatively cheap.

This is a multi-tank racking system. The water continually circulates. The water in each tank is replaced up to 20 times an hour. It’s a closed water recirculation system which means it stays within itself, if you like. It goes through course filters, a mechanical filter of 100 microns [0.1 mm], through a 25 micron screen filter, then it also goes through a de-nitrification process where the ammonia [from the fish excrement] is taken out of the water. Activated charcoal is used to remove any organic acids or chlorine. And then round and round through that up to 20 times an hour. So the water is dropped in through these blue overhead pipes, through the back, over a weir, down into a catchment gutter that runs down the back, and round and round.