Catfish: How do they taste?

I have pondered this question considerably. But as my field of expertise is neuroscience rather than the culinary arts, the following explanation is not one arrived at following a lazy afternoon on the banks of the Mississippi with can of worms, fishing line, and frying pan in tow. Rather, it is one arrived at following an engaging lecture given by a researcher at the Monell Chemical Senses Center in Pennsylvania.

For us, it is a jerk at the end of our fishing pole or perhaps the cheerful clatter of a dinner bell, that signals that we should go wash our hands, pull up a chair, and grab our forks. For the catfish, however, who do not have poles and live in an environment conducive to the rusting of dinner bells, it is taste receptors that signal that it's time to eat.

In fact, catfish have many taste receptors. These taste receptors reside on tastebuds. Unlike humans, whose tastebuds are limited to the tongue, catfish have tastebuds on the outside of their bodies. Tastebuds line the head, flank, lips, and whiskers and it has been approximated that each whisker is the home of 100,000 taste receptors. Such profuseness makes it unbearable to resist comparing the catfish to that of a giant swimming tongue.

So what is a receptor? And how does it tell the catfish that dinner is served? Although in poor taste, we return to the fishing pole analogy. The worm at the end of the pole is like the receptor and the fish biting the worm is analogous to the activation of the receptor. In the case of the catfish, it is an amino acid (not another catfish) that binds to the receptor. The binding of an amino acid, like the hooking of the fish, indicates a high probability of a meal. When the fish is hooked he flails about and in turn causes movement on up the fishing line until it jerks about in the fisher's hands. The fisher, ignoring the possibility that he could be taking a catnap, receives the "dinner bell" message and begins to reel in his line. In the case of the catfish receptor, binding of the amino acid causes a signal to be transported down an innervating neuron and through a neural pathway to the brain where it also signals the "dinner bell." In both cases the respective dinner bells signal preparation and initiation of feeding. The fisher responds by plopping the fish in the frying pan and sauteing it until it is crunchy? Flaky? Tangy? Or whatever his preference, pulling out his fork, and chowing down. For the catfish, life is perhaps a little simpler; he just begins to open and close his mouth in a chomping-like motion. For the catfish, this mouth movement is hopefully not toward a hook entangled worm.