Lateral line used for wake tracking

[mattc]

There's an interesting paper in the Journal of Experimental Biology on wake-tracking by piscivorous cats. In a nutshell, it shows that the lateral line appears to be more important in wake tracking than external gustation (ie. taste buds etc).

Matt

The importance of the lateral line in nocturnal predation of piscivorous catfish.
Pohlmann K, Atema J, Breithaupt T
J Exp Biol. 2004 Sep 1; 207(Pt 17): 2971-8

In a previous study we showed that nocturnal piscivorous catfish track the wake left by a swimming prey fish to locate it, following past locations to detect the present location of the prey. In a wake there are hydrodynamic as well as chemical signatures that both contain information on location and suitability of the prey. In order to determine how these two wake stimuli are utilised in prey tracking, we conducted experiments in catfish in which either the lateral line or the external gustation was ablated. 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, albeit their attacks were delayed. The external taste sense, which was reported earlier to be necessary for finding stationary (dead) food, seems to play a minor role in the localisation of moving prey. Our finding suggests that an important function of the lateral line is to mediate wake-tracking in predatory fish.

[coelacanth]

In a previous study we showed that nocturnal piscivorous catfish track the wake left by a swimming prey fish to locate it, following past locations to detect the present location of the prey. In a wake there are hydrodynamic as well as chemical signatures that both contain information on location and suitability of the prey.

I know this has been previously shown in Pinnipeds, and I'm sure we all agree that anything some fluffy with an evolutionary history measured in mere tens of millions of years can do, a Catfish can do far better. I'd also like to know more about the electrosensory capabilities of some of these Catfish, given that for some of them Gymnotoids appear to be a major food source.