It was once believed that venom production had evolved in around 200 different fish species, however, new research has suggested that they're much more widespread, with 1500-2000 species presumed venomous.
Venoms are a popular target for scientists looking for potential molecules or proteins to study for use in the production of drugs, something known as bioprospecting. Most studies have focused on snake venoms, which have led to the development of a number of drugs to treat strokes and cancers.
The scientists who made the discovery produced an evolutionary family tree known as a phylogeny which allowed them to predict which groups were most likely to have venom, which means bioprospectors can examine the fish to see if they could lead to useful new drugs.
This item was first published in the November 2009 issue of Practical Fishkeeping. It may not be reproduced without written permission.