Austin, TX -- U.S. researchers said Monday they have found that zebrafish can learn to prefer one fish color pattern over another.

Researchers at the University of Texas said the work extends the utility of zebrafish to studies of behavior and evolution.

In the experiment, they chose fish that carried drastically different color patterns -- either blue and gold stripes or an absence of stripes and a uniform mother-of-pearl color. This difference was the result of a single DNA base change in the fish's genome.

To determine whether genes or the environment determine individuals' preferences, the investigators raised subject fish either with other fish of their own color or with fish of the alternate color. When subject fish later were allowed to choose the color of fish with which to associate, they greatly preferred whichever color pattern they had been raised with -- irrespective of their own color.

This learned social preference not only could impact the survival and reproductive success of individual fish, it also suggests the knowledge of zebrafish genetics will afford researchers an opportunity to see how genes, development, and environment lead to behaviors that influence social interactions.