- Range:
Blue = current range
Hollow circles = former range
A map showing counties with designated critical habitat for this species may be found
the the Kansas Wildlife Refuge
- Status in Kansas:
Endangered
- North American Status:
(From NatureServe)
This is a northern range
species in North America that is generally stable except for some edge of range declines
to extirpation in Minnesota, Illinois, and Ohio. It has a range extending from Indiana and
Michigan to southeastern Minnesota, Iowa, southeastern Kansas, Missouri, Oklahoma,
Arkansas and Kentucky, and has apparently been extirpated from Ohio. Out of 28 stations
recently surveyed along the Tittabawassee River of Michigan, a tributary to the Saginaw,
the species was present at 16 and abundant at eight stations. Currently, the species is
found at 11 sites in five southeastern Wisconsin river systems. It also occurs in the Fox
River drainage in the southwestern part of the state. In Kansas, range is restricted to
the Spring River in the southeastern corner of the state and the mussel is considered a
peripheral species. In Missouri, range formerly covered areas north of the Missouri River.
Current range is the streams that flow north off the Salem and Springfield Plateaus. The
first record from Minnesota was from the Cannon River in 1987. Within the Cannon River
watershed, extant populations were discovered in the Straight River, Wolf Creek and the
Cannon River proper. The largest population was found within the tailwaters of an old mill
dam on the Straight River; 2 live and 3 dead shells were found in June 2005. Although
presently limited in distribution within the drainage, past distribution appears to have
been much wider. Subsequent to the Cannon River survey, sites have been found in other
river systems within the southeastern corner of the state, the Zumbro and tributaries to
the Root. In 1800 sample sites across all of Minnesota (almost 500 from the St. Croix
drainage and drainages in southeastern Minnesota) the species was found in 219 sites in
five primary tributaries to the Mississippi River: the Cannon, Cedar, Root, Upper Iowa,
and Zumbro River systems; with no relic shells in any other systems. In Iowa, range is the
upper reaches of rivers in the northeastern third of Iowa. Although some records are
available from large rivers (judging from recent records of this species from the
Mississippi River at Davenport, Muscatine, Prairie du Chien and Keokuk, it is rarely found
in large river habitats. There have been no records in the state of Ohio. Although some
records also exist in Lake Erie tributaries, none of these are from Ohio. The ellipse was
historically found in the northern half of Illinois, particularly in the northeast.
However, many streams in that part of Illinois have been negatively effected by urban
development and agricultural impacts and many populations have been extirpated. The
ellipse is now relatively uncommon in Illinois. A few apparently healthy populations can
still be found in tributaries to the Kankakee, Fox, Mackinaw, and Vermilion (Illinois
River drainage) rivers. This mussel is rare in Indiana occurring only at a few sites
primarily in streams draining into Lake Michigan. A few historical records exist for
glacial lakes in the headwaters of the Tippecanoe River.
- Comments:
As a full-grown mussel, the ellipse is still relatively small. The straw-colored
shell has numerous dark rays that radiate from the umbo of the shell. It is a mussel
restricted to small, upland Ozark streams. In Kansas, it is only found in the Spring and
Marmaton rivers. It is dimorphic with the male being narrower in height than the female.
Typically, the females release glochidia in the early morning hours. The glochidia must
attach to a host fish or they will perish. The number of glochidia released per female is
directly related to her size.
- Fish Hosts:
Johnny darter, orangethroat darter, fantail darter and banded sculpin
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