Ellipse
Venustaconcha ellipsiformis (Conrad)

Status: State Threatened (August 1, 1989).

Occurence: Occurs in the following rivers in Wisconsin: Ashippun, Bark, Crawfish, Manitowac, Meeme, Milwaukee, Mukwonago, Mullet, Oconomowoc, Pigeon, south fork of the Popple, Rock, Sugar, and Yellow. Also found in Cedar Creek, Jericho Creek, O'Neil Creek, Sugar Creek. This species may yet be found in rivers for which only historical records now exist. Refer to the species map.

Aid to ID: Shell is elliptical, heavy and rough having a sharp crease near the posterior ridge. The outside of the shell is greenish-yellow with numerous wavy, continuous rays of dark green. Pseudocardinal and lateral teeth are heavy. Umbro sculpture consists of three or four fine double looped concentric ridges. The nacre is bluish-white to white. The ellipse is small, up to 89 mm (3.5 inches) long.

Habitat: Inhabits small to medium sized streams with good current, in shallow water, on sand or gravel bottoms.

Management Considerations: Because it inhabits small streams and headwaters, this mussel is particularly vulnerable to siltation and pollution from runoff. Habitat protection and water quality improvements would benefit this species. Increased development along waterways in southeast Wisconsin is of particular concern for the continued existence of the species.

The content for this page was originally presented in the Endangered and Threatened Invertebrates of Wisconsin, a free publication available by contacting the Endangered Resources Program.