Let me begin this week’s article with a few questions. How would you define a river? How is a stream different than a run? What is a brook? How about a wash, bayou, or rio? The answer is quite simple; it has to do with where you live. As settlers moved westward, cultural influences played a major role in determining how natural features in the landscape were named. Bayous follow historical French settlement patterns along the Gulf Coast and up Louisiana streams. Similarly, the Spanish-derived term rio, as in “Rio Grande”, traces the early advances of conquistadors into present-day northern New Mexico. Washes, in the southwest reflect the intermittent rainfall of the region, while streams named swamps, “Dismal Swamp,” along the Atlantic seaboard highlight where the coastal plain meets the Appalachian Mountains. However, in northeastern Ohio, you can step over a brook, jump over a creek, wade across a stream, and swim across a river.
Now that we have that all straightened out, how many times have you been walking along or in a small stream and have seen the small fish darting around? Most of the time they look brown and un-interesting; however, upon closer inspection the breeding colors of the Rainbow Darter, Green Darter, Rainbow trout, Dace, and Stonerollers are something to behold. Along with the macro invertebrates, these small and sometimes very large fish make up an aquatic community that can tell us a great deal about water quality and the overall health of any stream. But like anything else in nature, we must understand some basic concepts about streams and stream habitat before we can highlights some of these beautiful fish.
Stream habitat, refers to areas that fish and other aquatic organisms need for concealment, breeding and feeding. This can include large woody snags, boulders, rock ledges, undercut banks, overhanging vegetation, brush and tree roots found along stream banks. These areas can occur in three distinct areas of a stream, a pool, riffle, and run. All three areas are home to different fish species, so it is important that you look at all three areas to get a complete picture of the stream community.
A small fish, rainbow darters only grow to 3 inches long. They can be a very brightly-colored fish, depending on their sex and whether it is breeding season. Rainbow darters (Etheostoma caeruleum) are native to Ohio. Year-round, this species inhabits small rivers and streams in Ohio. Rainbow darters have been widely located in vast numbers in the Ohio and the tributaries of the Great Lakes. Rainbow darters prefer the fast-moving currents of shallow riffles in creeks and small rivers. They also have a preference for gravel or rocky-bottom streams. Typically, adult fish are found in faster and deeper running waters, while younger rainbow darters are more common in slower, shallower areas and pools. Rainbow Darters are an indicator of very clean, clear water.
Western blacknose dace (Rhinichthys obtusus) have an olive to dark brown back, lighter sides, and a cream colored belly. They also have black blotches scattered across their back and sides. They have a dark mid-lateral stripe from the snout to the base of the tail. This stripe is black or brown in females (and young) and a rusty red in males. The blacknose dace is found in small brooks and streams in Northeast Ohio having moderate or high gradients, clear waters, and clean substrates composed of sand, gravel, and cobble. These fish are typically found in fast water where there are overhanging roots or undercut banks. This particular Dace is tolerant of increased pollution.
Central Stoneroller (Campostoma anomalum) adult males and females look similar. The upper half of their bodies is dark greenish; gradually fading to a whitish belly. Small, randomly scattered dark spots are often present along the length of the body and the fins are generally colorless. During the spawning season, males develop a slate-gray colored back, a yellowish underside, and small blue spots on the head. Central stoneroller preferred habitat is pools or riffles with gravel or rubble substrate in small to medium-sized streams. They prefer cool, clear water with moderate to fast currents. Central stonerollers are very sensitive to water pollution or increased debris which may prevent algae from growing.
Then there are the trout, but we will leave that topic for another article.
So next time you are stepping over a brook, jumping over a creek, wading across a stream, or swimming across a river, maybe you will see one of these colorful inhabitants.
