Nerdy New Darter Question

Hi,

What is the distinction between the Etheostoma and Percina genera?

I wasn't sure which forum might be interested in this question. It's a nerdy question from an amateur, new to natives fish lover.

Thanks in advance,
Guy

Broadly, Percina species tend to be larger and not as splashily colored, and prefer deeper and/or faster water compared to Etheostoma species. There are plenty of exceptions to that statement, however.

I can say that Percina are generally much more pelagic. One percina that really takes this one step farther is stictogaster, the frecklebelly darter. It is much like a minnow in behavior, rarely ever resting on the bottom.

My experience with Percina is somewhat different than Bruce's. Most of the Percina that I have dealt with in my neck of the woods, with the exception of logperch and slenderhead darters are usually associated with slower water, and bankside cover. I think they can be very variable in their habitat preferences.

Morphologically, Percina have a bit of a "swim bladder", and the only other thing that comes to mind are the presence of scutes on their undersides in almost all species. Etheostoma lack scutes, and most if not all don't have much of a "swim bladder" I am sure there are many more differences, but these are about all I can think of. Oh, and like Bruce mentioned, size and color. Most Percina are drab in color, and breeding males don't tend to explode with color. One notable exception tangerine darter quite colorful for a Percina. Percina are generally larger, but again with several exceptions.

Thank you Matt and Bruce. I am new to all of these stream fishes, and new to using a lot of taxonomic nomenclature. I find it helpful to have a working concept of what differentiates things.

I will be sure to look for the scutes, should I be fortunate enough to closely observe them.

Yes, I was enamored with pictures of a tangerine darter that emerged recently, and I thought it curious that most other pretty darters were classified in the genus Etheostoma. I would say, just looking at pictures, that there is generally a subtle difference in body shape, with the Percinas being somewhat more streamlined in appearance.

Thanks again.

Yeah, Bruce and Matt have pretty much summed it up. Percina will also always have a complete and straight lateral line, with one or two pored scales extending on to the caudal fin. Like Matt said, they have scutes on their venter -- one or two of these appear between the bases of the pelvic fins (known as a stellate scale), which are present in both sexes. I think you're right in suggesting that Percina are, by and large, more elongate than Etheostoma. Most species don't display the degree of sexual dichromatism seen in Etheostoma, either.

Morphologically, Percina have a bit of a "swim bladder", and the only other thing that comes to mind are the presence of scutes on their undersides in almost all species. Etheostoma lack scutes, and most if not all don't have much of a "swim bladder" I am sure there are many more differences, but these are about all I can think of. Oh, and like Bruce mentioned, size and color. Most Percina are drab in color, and breeding males don't tend to explode with color. One notable exception tangerine darter quite colorful for a Percina. Percina are generally larger, but again with several exceptions.

The Gilt & Roanoke Darters are quite colorful as well.

I would add I think Matt understated the air bladder difference. While it is true not all Percina have a well developed air bladder (gilt darter) they all have at least some what of an air bladder allowing them to stay off the bottom with far less effort than any Etheostoma sp. Also some obviously have pretty well developed air bladders allowing them to hover like a sunfish especially his example of P. stictogaster. Also dusky, longhead, and blackbanded are a few more Percina with pretty well developed air bladders that rarely sit on the bottom.

I would add I think Matt understated the air bladder difference. While it is true not all Percina have a well developed air bladder (gilt darter) they all have at least some what of an air bladder allowing them to stay off the bottom with far less effort than any Etheostoma sp.

I don't feel as though Matt understated it, as there are a few species of Percina that lack gas bladders completely (= P. antesella and P. roanoka). In fact, I'd say more Percina species need to be analyzed for the presence/absence of gas bladders (make a good undergraduate project).

See: Evans, J.D. and L.M. Page. 2003. Distribution and relative size of the swim bladder in Percina, with comparisons to Etheostoma, Crystallaria, and Ammocrypta (Teleostei: Percidae). Environmental Biology of Fishes 66: 61-65.

Cool. I've learned something about 2 genera.