Ever wondered how many catfish there are? Matt Clarke has the answer.

There are now over 3,000 species of catfish spanning more than 36 families, plus many more species waiting to be described.

Hundreds of these are commonly kept by fishkeepers. Catfish account for one out of every 20 known vertebrate animals.

Thanks to projects such as the All Catfish Species Inventory (ACSI), which is funding research by catfish ichthyologists, descriptions of new species are at an all-time high.

Among the most notable recent discoveries is Lacantunia enigmatica, which was placed in its own family.

This item was first published in the September 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.