Macalester College

St. Croix Endangered Mussels

Information on this page is from the US Fish and Wildlife Service Endangered species pages.

 

Higgins Eye

Lampsilis higginsii

The Higgins eye mussel (Lampsilis higginsii (Lea, 1857)) was originally distributed throughout the upper Mississippi drainage (from the confluence of the Ohio River to Minneapolis/St. Paul, MN). This species was one of the first freshwater mussel species to be declared endangered under the Endangered Species Act because of an estimate 50% reduction in its range. Since the original recovery plan developed in 1983, new research has extended the known range at the time of its listing by 180 river miles. During that time new threats were also discovered including the invasion by the zebra and quagga mussels. An updated recovery plan was prepared in 2003, written by Dan Hornbach. In the revised plan the impact of zebra mussels was considered so important that additional essential habitat areas (areas deserving special protection) were added for this species. Three of these areas are in the St. Croix River - Prescott, Hudson and Franconia.

More information regarding the factors that may have lead to the decline of the Higgins eye mussels can be found in the flyer produced by the Fish and Wildlife Service. A PDF copy of the flyer can be found here. The Recovery Plan for this species as a PDF is at Higgins eye pearlymussel recovery plan: first revision - PDF May 2004

Sheepnose

Plethobasus cyphyus

"The sheepnose is a freshwater mussel found across the Midwest and Southeast.  However, it has been eliminated from two-thirds of the total number of streams from which it was historically known. Today, the sheepnose is found in Alabama, Illinois, Indiana, Iowa, Kentucky, Minnesota, Mississippi, Missouri, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin.

The sheepnose is a medium-sized mussel that grows to about 5 inches in length. It lives in larger rivers and streams where it is usually found in shallow areas with moderate to swift currents flowing over coarse sand and gravel."

More information regarding the factors that may have lead to the decline of the sheepnose mussels can be found in the flyer produced by the Fish and Wildlife Service. A link to the flyer can be found here. The Recovery Plan for this species is being developed.

Snuffbox

Epioblasma triquetra

The snuffbox is a small, triangular freshwater mussel that is found in Alabama, Arkansas, Illinois, Indiana, Kentucky, Michigan, Minnesota, Missouri, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. It lives in small to medium-sized creeks in areas with a swift current, although it is also found in Lake Erie and some larger rivers.

More information regarding the factors that may have lead to the decline of the snuffbox mussels can be found in the flyer produced by the Fish and Wildlife Service. A link to the flyer can be found here. The Recovery Plan for this species is being developed.

Spectaclecase

Cumberlandia monodonta

The spectaclecase is a freshwater mussel found in the Mississippi, Missouri, and Ohio River basins. Today, its range includes Alabama, Arkansas, Illinois, Iowa, Kentucky, Minnesota, Missouri, Tennessee, Virginia, West Virginia, and Wisconsin. With few exceptions, spectaclecase populations are highly fragmented and restricted to short stream reaches.

More information regarding the factors that may have lead to the decline of the snuffbox mussels can be found in the flyer produced by the Fish and Wildlife Service. A link to the flyer can be found here. The Recovery Plan for this species is being developed and an outline of the plan can be found at www.fws.gov/midwest/endangered/clams/spectaclecas/pdf/SpectaclecaseRecoveryOutline.pdf

Winged Mapleleaf

Quadrula fragosa

At one time the federally endangered winged mapleleaf inhabited at least 34 river systems in 12 states (USFWS 1997). Quadrula fragosa (Conrad 1835) is now thought to occur in select reaches of St. Croix River, Wisconsin, Kiamachi River, Oklahoma, and Bourbeuse River, Missouri. One of the last known reproducing populations occurs in the St. Croix River where the river forms the border between Minnesota and Wisconsin. Until very recently winged mapleleaf were thought to occur only downstream of the St. Croix Falls dam. In 1999 and 2001 Hove et. al found dead valves above the St. Croix Falls Dam, suggesting a greater distribution of this mussel in the St. Croix. We are currently examining possible relocation sites above the dam for Winged Mapleleaf mussels that be produced in propagation trials.

More information regarding the factors that may have lead to the decline of the winged mapleleaf mussels can be found in the flyer produced by the Fish and Wildlife Service. A PDF copy of the flyer can be found here. The Recovery Plan for this species as a PDF is at http://ecos.fws.gov/docs/recovery_plan/970625.pdf. Dan Hornbach was a member of the recovery team developing this plan.

Hove, M. C., L. A. Cunningham, K. G. Esse, and D. J. Hornbach. 1999. Range extension of the federally endangered winged mapleleaf: valves collected from upper St. Croix River, Minnesota. Triannual Unionid Report 18: 9.

Hove, M. C., D. C. Allen, R. S. Derhak, K. M. Swenson, J. E. Thomas, and D. J. Hornbach. 2001. Second collection of winged mapleleaf valves from the upper St. Croix River. Ellipsaria 3(2): 11-12.

U.S. Fish and Wildlife Service. 1997. Winged mapleleaf mussel (Quadrula fragosa) recovery plan. Fort Snelling, Minnesota. 69 pp.