Catfish taste with their whole bodies.

Catfish are often called “swimming tongues” because they have an extraordinary sense of taste that extends far beyond their mouths. These fish can have hundreds of thousands of taste buds distributed across their bodies, with especially high concentrations around their mouth and barbels, aka the whiskerlike feelers around their mouths. Those receptors allow them to detect chemicals dissolved in the water, helping them locate food even when they can’t see it. 

This ability is especially useful because many catfish are active in murky water, where visibility can be very limited. Their taste receptors are particularly sensitive to amino acids and other chemicals associated with potential food, helping them detect and locate prey such as insects, worms, crustaceans, and small fish. Their body-wide taste system also enables them to continuously sample the water around them as they search for food.