While exploring a creek near Youngstown, Ohio, I came across one of these neat little fish for the first time. Greenside Darters have an elongated body with a long and rounded snout. Their body typically has U- or W-shaped blotches along the side. They typically grow to be about four inches long.
This fish is an insectivore, mainly feeding on insect larvae, crustaceans and other invertebrates found on the bottom of the waterways that it resides in. The name “darter” refers to the way this fish moves. Rather than swimming like most fish, the darter darts forward then sinks to the bottom.
It does this because its air bladder is greatly reduced, interfering with the darter’s ability to stay afloat. This allows it to live in riffle areas where fish with air bladders would have the disadvantage of floating and being swept away by the water current. When a darter comes to rest, its fins and tail fin prop up its body in sort of a tripod position with its head angled upward.
Greenside Darters primarily live in larger streams with cobble, pebble, and gravel on the streambed. In order to survive, they need waterways with high water quality. Due to this attribute, they are often viewed as an indicator of good water quality.
This was a great and unexpected creature to come across while out and about.