John Lynch beat me to this story about catfish feeding on land, so I’ll be brief. It shows how the eel catfish, Channallabes apus, can manage to take an aquatic feeding structure and use it to capture terrestrial meals. Many fish rely on suction feeding: gape the mouth widely and drop the pharyngeal floor, and the resulting increase in volume of the oral cavity just sucks in whatever is in front of the animal. That doesn’t work well at all in the air, of course—try putting your face a few inches in front of a hamburger, inhale abruptly, and see how close you come to sucking in your meal. So how does an aquatically adapted feeder make the transition to eating on land?
The pictures and the movie make it clear. The fish is making the same pharyngeal movements, but it’s also bending its head ventrally and pinning the prey between mouth and substrate before slurping it in.
You can see what it’s doing much better in the movie below. I’ll warn you that it’s a bit alien looking, with this slimy, beady-eyed creature draping its barbel-ringed mouth over a small piece of cod, gulping a few times, and then slithering away.
The authors make the point that the same anatomical features that make it possible for the eel catfish to snack on terrestrial prey are also found in fossil tetrapods, like Ichthyostega.
Van Wassenbergh S, Herrel A, Adriaens D, Huysentruyt F, Devaere S, Aerts P (2006) A catfish that can strike its prey on land. Nature 440(7086):881.