CONSERVATION ASSESSMENTS FOR Lasmigona compressa, Lasmigona costata, Ligumia 
recta, and Venustaconcha ellipsiformis (UNIONIDAE) IN EIGHT NATIONAL FORESTS IN 
MINNESOTA, WISCONSIN, AND MICHIGAN.

Marian E. Havlik 
Malacological Consultants, 1603 Mississippi Street, La Crosse, WI 54601-4969    

Lasmigona compressa (creek heelsplitter), Lasmigona costata (flutedshell), 
Ligumia recta (black sandshell), and Venustaconcha ellipsiformis (ellipse shell) 
are currently designated as Forester Sensitive Species in the Chippewa and 
Superior National Forests in 7 Minnesota counties, Chequamegon-Nicolet National 
Forest in 11 Wisconsin counties; and in the Ottawa and Hiawatha National Forests 
in 11 Upper Michigan counties, and in the Huron-Manistee National Forest in 12 
Lower Michigan counties.   These unionid species are known to live, or have 
lived, in some of these Forests.  An extensive literature review, museum visits, 
and interviews with Forest personnel were done to prepare a Conservation 
Assessment to suggest management actions to conserve each of these species 
within these eight National Forests.  The history of the taxonomic names used 
for each species was determined, as well as the known global distribution for 
each species.  Difficulties were frequently encountered with inadequate data on 
museum and literature specimens.  Sometimes one or more of these species was 
known from a single river within a Forest, but their relative abundance and 
distribution usually differed widely by forest, and in various river systems.  
In some areas these four species were represented by chalky shells only.  Maps 
were prepared for each species showing all known locations (by county) of each 
of the four mussel species in each of the three states.  

Lasmigona compressa is only known from 28 of 87 Minnesota counties (32.2%), but 
from 50 of 72 Wisconsin counties (69.4%), and 59 of 83 Michigan counties 
(71.1%); L. compressa has been recorded from 15 states.  Venustaconcha 
ellipsiformis has only been recorded from 8 states, but had the widest 
distribution in Michigan (32 of 83 counties, 38.6%).  V. ellipsiformis was 
recorded from 18 of 72 Wisconsin counties (25%), and from 8 of 87 Minnesota 
counties (9.2%).  The ellipse shell had the most limited distribution in the 
National Forests under consideration.  Lasmigona costata occurs throughout 
Wisconsin (known from 70 of 72 counties, 97.2%), but is only known from 47 of 83 
Michigan counties (56.6%), and 38 of 87 Minnesota counties (43.7%); L. costata 
is known from 23 states.   Ligumia recta is known from 58 of 72 Wisconsin 
counties (80.5%), 38 of 87 Minnesota counties (43.7%) and 36 of 83 Michigan 
counties (43.4%).   L. recta have been recorded from 25 states.  Among the 
nearly 120 fish species known from the rivers in these eight National Forests, 
at least 49 fish species (41.5%) have been recorded as hosts for these four 
Forester Sensitive mussel species.  The host fish were evaluated for their 
presence in each forest, and in the rivers involved, which drain to the 
Mississippi River, Great Lakes, and Hudson Bay; more host fish work is needed.  
Lack of field research seems to be the biggest reason why there is the 
perception that population distributions have decreased in these National 
Forests, yet there seem to be few serious impacts from agriculture or industry.  
BMP’s and timber harvest buffers seem quite restrictive in all forests.  More 
field work is urgently needed.  

	Keywords: unionid species, mussels, conservation assessments; National 
Forests