Redfin Shiner (Lythrurus umbratilis)

Status: State Threatened (1989).

Occurrence: At the northern limit of its range in the Mississippi River and Lake Michigan drainage basins, disjunctly distributed in the southern half of Wisconsin. A map outlining Pre-1977 and 1997 to Present Distribution is available.

Aid to ID: Deep-bodied, thick-skinned, whitish shiner with small, closely-crowded predorsal scales. Snout bluntly pointed. Black bluish gray dorsally, sides and belly silvery. Breeding males have a bright blue body, red fins and white or pale gray on top of head, looking like the red shiner (Notropis lutrensis) which has much larger scales. Also resemble the ribbon shiner (N. fumeus), with which they co-exist, but distinguishable from that species by their deeper body, smaller eye, black spot at dorsal fin base, and uniform pigmentation on upper scales. Adult length: 2.2 inches (56mm).

Habitat: Found occasionally in clear water, but more often in turbid areas at depths of 4-60 inches (0.1-1.5m) over silt, gravel and rubble. Occur in pool areas of low-gradient, medium-sized streams.

Food Habits: Seen in schools near surface, redfin shiners eat filamentous algae, bits of higher plants, aquatic and terrestrial insects.

Natural History: They have an intimate and widespread reproductive association with sunfish (Lepomis spp.) which they need to reproduce. Spawning runs from early June to mid-August in nests and nesting territories of sunfish. They become sexually mature in their second or third summer.

Management Considerations: During most of the year redfin shiners can tolerate siltation, but they require clear water during spawning, which may factor into their scant occurrence. See summary fish management section.

Information compiled from publication ER-091.