About five years ago, a walking catfish flopped its way up to the front steps of my mother's house. Walking catfish are a nonnative species that has proliferated in the canals and wetlands of south Florida after being first discovered in the late 1960s. Knowing that I have an interest in such things, she immediately called me and informed me she had the homely creature in a bucket. "You want it?" she asked. In hindsight, it was an odd offering for someone to make. And yet, I immediately said yes.
At the time, I had been maintaining an aquarium with another nonnative species-- a red-eared slider. I figured the two would make good bedfellows and introduced the walking catfish into the tank. I've had it ever since. Often, when getting elbow-deep cleaning the aquarium of green algae, I have seriously regretted my decision. But now, with my keen eye on energy use, I look upon this situation ever more critically.