Redfin Shiner (Lythrurus umbratilis)
This species reaches its northeastern limit in the Great Lakes drainages of western New York where it is present in tributaries along the Lake Erie and Lake Ontario Plains. The subspecies cyanocephalus ranges from Texas and Louisiana through the eastern tributaries of the Mississippi to southeastern Minnesota and southern Ontario. Its overall range extends southwestward into the central Mississippi region where it intergrades with N. u. umbratilis in west-central Arkansas.
The redfin shows a preference for streams with moderate or low gradient over sand and gravel bottom with some vegetation.
The reproductive behavior of the redfin shiner was studied in Wisconsin. In the introduced populations studied, the redfins spawned over nests of the green sunfish, Lepomis cyanellus. Male redfins defended territories over the sunfish nests, 5 to 8 cm above the bottom. Solitary males defended large territories but when several males were present the territories were smaller. Small males crowded at the periphery of the spawning areas or above the terri- tories of the larger males. Defending males chased and butted intruders. Sometimes, two males swam parallel to each other for as much as 2 meters, butting each other as they went. Females remained outside the clusters of territorial males. As the female approached, a male would join her and they would swim together, undulating wildly as the spawning took place.
Most of the spawning took place between 10 am and 2:30 pm. Sometimes, the shiners formed dense aggregations in which the males' territories were only slightly larger in diameter than their length. Females swam through these aggregations and spawning occurred in the midst of the males fighting and chasing each other. Aggregation occurred most frequently when the sunfish were spawning and the redfin shiners were not pursued by the male sunfishes although bluegills and other species of shiners were. It is possible that the redfin shiners were not bothered because their territories were maintained above the bottom. This suggests that the association of the shiners and the green sunfish is a normal occurrence. Milt and ovarian fluid from the sunfish attracted the shiners and triggered spawning behavior and it was suggested that the shiners depend on the presence of spawning sunfish for initiating their spawning activities. In Ohio, redfin shiners were found spawning over sand and gravel in sluggish riffles and pools with some current. Outside of the spawning season the redfins preferred pools with some vegetation.
This species is uncommon in New York and appears to be present in fewer localities than it was a few years ago.
Distribution of redfin shiner in NY state.
A 169 KB image of the redfin shiner is also available for download.
The above species description was taken out of "The Inland Fishes of New York State" by C. Lavett Smith, published by the New York State Department of Environmental Conservation, 1985.