Predatory catfish use lateral line for wake-tracking


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Predatory catfishes use their sensitive lateral line sensory system for tracking the wake caused by prey as they swim after dark, says a new study.

Three scientists from the University of Konstanz in Germany will report their findings in September's Journal of Experimental Biology.

Pohlmann, Atema and Breithaupt have previously shown experimentally that noctural piscivorous cats can track the wake of prey fish and use past locations to detect the present position of their prey.

The team have recently completed a new experiment to determine how the catfish respond to stimuli based on chemical signatures in the wake of prey, and to hydrodynamic signals produced by the prey fish, by ablating the lateral line or external gustation (the sense of taste).

By deactivating either the lateral line system or the sense of taste on the barbels, the scientists should be able to work out which of the two senses were most important in prey tracking.

The results show the importance of the lateral line system in wake tracking:

"We found that a functional lateral line is indispensable for following the wake of swimming prey.

"The frequency of attack and capture was greatly diminished and the attacks that did occur were considerably delayed when the lateral line was ablated.

"In contrast, catfish with ablated external taste still followed the wakes of their prey prior to attacking."

For more details see: Pohlmann, K., Atema, J. and T. Breithaupt. (2004) - The importance of the lateral line in noctural predation of piscivorous cafish. Journal of Experimental Biology, September 2004. 207. 2971-2978.