(interior)
(exterior)
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Note: Red text
is defined in the Glossary
Description
The eastern creekshell is very similar to the Carolina creekshell.
The periostracum is yellow to dark
golden brown with green rays. However,
the rays of the eastern creekshell are usually broken instead of
continuous. These rays may cover the entire shell
or be restricted to the posterior slope.
A dark layer of diatoms and algae may be obscure the true colors
of the shell. This species also displays sexual
dimorphism in shell shape with the posterio-ventral
margin of the female becoming expanded with age, while the
ventral margin of the male remains
straight. The expansion demonstrated in eastern creekshell is usually
more exaggerated than that seen in the Carolina creekshell. There
are two pseudocardinal teeth in each
valve; however, the posterior
tooth in the left valve and
the anterior tooth in the right
valve may be vestigial. The
lateral teeth are straight and well
developed; two in the left valve and one in the right. Finally,
the outer margins of the marsupium in the eastern creekshell are
black; while, the outer margins of the marsupium in the Carolina
creekshell are ivory colored.
Distribution (see
map)
This species ranges from the Altamaha River Basin, Georgia, north
to the Cape Fear River Basin. Distribution by County: Catawba River
Basin: Burke Co. (Johns River) Union Co. (Waxhaw Creek, Six Mile Creek).
Yadkin-PeeDee River Basin: Anson Co. (Brown Creek); Cabarrus Co. (Coldwater
Creek); Montgomery Co. (Clarks Creek, Barnes Creek, Little River Subbasin,
and Lake Tillery); Randolph Co. (Barnes Creek, Little River Subbasin);
Stanly Co. (Bear Creek Subbasin); Union Co. (Goose Creek Subbasin,
North Fork Crooked Creek, Richardson Creek, Rocky River). Cape Fear
River Basin: Alamance Co. (Haw River Subbasin, including Stinking
Quarter Creek, Mary's Creek, Back Creek, and Cane Creek); Bladen Co.
(Cape Fear River); Brunswick Co. (Town Creek); Chatham Co. (Rocky
River, Bear Creek); Cumberland Co. (Cape Fear River); Duplin Co. (Northeast
Cape Fear River Subbasin); Harnett Co. (Cape Fear River); Moore Co.
(Deep River); Orange Co. (Phils Creek); Pender Co. (Black River, Little
Coharie Creek, Six Runs Creek); Rockingham Co. (Haw River). Waccamaw
River Subbasin: Columbus Co. (Big Creek). NOTE: All headwater areas
that flow into these occupied habitats should receive special management.
Habitat Preferences
R. I. Johnson (1970) described what he considered the species
common habitat features as "mud or soft sand, particularly where
rich in vegetable detritus, in small rivers and creeks."
Life History
This species is bradytictic. Little
else is known of the life history of the eastern creekshell.
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