
(interior)

(exterior)
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Note: Red text
is defined in the Glossary
Description
This species was described by Conrad in 1835 from the Schuylkill
River and other streams in Pennsylvania. The green floater is a
small species; adults usually are less than 55 mm in length. Shells
are thin and subovate or trapezoidal
in shape. Beaks are depressed, projecting
only a little above the hinge line,
and may have double-looped sculpturing. The periostracum
varies from dull yellow to brownish green. Numerous, variable width,
dark green rays may be visible on the
shell, especially in young specimens. The nacre
is white with a bluish iridescent tinge
posterior. In many specimens, yellow or salmon blotches occur in
the nacre, both centrally and near the beak
cavity. The shell is so thin that, when held up to a light
source, the colors and patterns of the periostracum
often show through the nacre. Hinge teeth
are moderately developed but very delicate, and the lateral
teeth may be incomplete or indistinct. The left
valve has two lamellate pseudocardinal
and two long, straight, thin, lateral teeth. The right
valve has one pseudocardinal and one lateral tooth. The left
valve often has an interdental projection.
Distribution
(see map)
This species has a widespread distribution from the Cape Fear
River Basin in North Carolina north to the Hudson River Basin, and
westward through the Mohawk River and the Erie Canal to the Genesee
River of New York. It also occurs in the New and Greenbrier rivers
in North Carolina, Virginia, and West Virginia.
Distribution by
County: Watauga River Basin: Watauga Co. (Watauga River Basin);
New River Basin: Ashe Co. (New River Basin); Alleghany Co. (New
River Basin). Neuse River Basin: Orange Co. (Eno River Subbasin),
Person Co. (Flat R. Subbasin), Durham Co. (Flat R. Subbasin), Wake
Co. (Swift Cr. and Little River subbasins). Roanoke River Basin:
Person Co. (Mayo Cr. Subbasin), Halifax Co. (Roanoke River); Northampton
Co. (Roanoke River); Rockingham Co. (Dan River Subbasin); Stokes
Co. (Dan River Subbasin). Tar River Basin: Granville Co. (Tar River
Subbasin), Nash Co. (Tar River Subbasin). NOTE: All headwater
areas that flow into these occupied habitats should receive special
management.
Habitat Preferences
The green floater inhabits small to medium size streams. It
is intolerant of very strong currents and often is found in quiet
pools and eddies with gravel and sand substrate (Ortmann 1919).
The green floater also has been found in canals. Walter (1954) found
this species living in water depths of one to four feet. In North
Carolina, the best populations are associated with good to excellent
water quality.
Life History
The green floater is one of a few species of freshwater mussels
that is hermaphroditic (individuals
contain both male and female gonadal
tissues). This species also is a bradytictic
breeder, with the reproductive season extending from August to May.
Host fish have not been determined
for the green floater. However, there is documentation for direct
transformation of glochidia into juvenile
mussels (Barfield and Watters 1998, Lellis and King 1998).
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