Fish o' the Day - redfin darter

Seems like time to talk about one of our darters. For the last couple of years, we've had undergrads out in our local streams pulling seines. For the most part, they've been conducting developing research projects for their ecology class, although we've had a few that have been out freelancing. For the most part, the focus has been on microhabitat studies - looking at the way that environmental parameters influence the darter assemblage in a particular stream. We find a good stream, identify a number of microhabitats that differ in current velocity, substrate, canopy cover, etc., and then sample the heck out of them to see what types of darters are there. Darters lend themselves well to this type of analysis, because they're what we have come to call "hunker down" fish. They're strictly benthic - even lost their swim bladder to demonstrate their commitment to life on the bottom. They also show a high degree of site fidelity. That means that if you find them somewhere, it's probably because that's where they want to be. In the process, we're building a decent picture of how different darter species are distributed.

Meet the redfin darter, Etheosoma whipplei. He's a handsome guy - and that's the breeding male that's pictured. They develop a distinctive pattern of red dots, and the banding of the dorsal fins really stands out too. Like most darters, they're small - three inches is a big one.

What our Sumter County studies are telling us is that the redfin is also a pretty capable guy. We find them in a wide range of microhabitats, and in a wide range of streams. We've worked abot ten streams now, and the redfin has been present in all but one. He's there too, we just haven't found him yet.