
(interior)

(exterior)
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Note: Red text
is defined in the Glossary
Description
This elongate freshwater mussel grows to approximately 86 mm long.
Shells are over twice as long as tall.
The periostracum is usually a waxy,
bright yellow over the entire surface in younger individuals. Older
individuals may have a brown discoloration on the posterior
end of the shell. The nacre
may range form salmon to white to an iridescent blue. The posterior
ridge is distinctly rounded and curves dorsally toward the
posterior end. Rays
are usually never present; however, one individual has been observed
with three wide, prominent green rays on the posterior third of
the shell in the Tar River Drainage Basin. Brownish growth rests
are clearly evident on the periostracum. The pallial
line and adductor muscle scars
are distinct. The posterior adductor muscle
scars are less impressed than the anterior adductor muscle
scars. The lateral teeth are long -
two on the left valve and one on the right valve. Two pseudocardinal
teeth are on each valve. On the left
valve, one is before the other with the posterior tooth tending
to be vestigial. On the right valve,
the two pseudocardinal teeth are parallel with the more anterior
one rather vestigial. The soft parts
including the incurrent and excurrent apertures
and the foot are typically white.
Distribution
(see map)
Johnson (1970) considers the range of the yellow lance to extend
from the Escambia Drainage Basin, east through parts of Florida
and north to the Susquehanna River in Pennsylvania. However, Johnson
synonymized many species under Elliptio lanceolata. Using the above
description, the yellow lance is known from the Rappahannock River
Basin in Virginia south to the Neuse River Basin of North Carolina.
This species appears to have been recently extirpated from Ruin
creek in Vance County and the Tar River in Edgecombe County.
Distribution by
County: Neuse River Basin: Wake Co. (Swift Cr. Subbasin), Johnston
Co. (Middle, Swift, and Mill creek subbasins), Tar River Basin:
Granville Co. (Tar River Subbasin), Franklin Co. (Fox, Crooked,
Sandy, Shocco creek subbasins and Tar River), Vance Co. (Tabbs Creek
Subbasin) Warren Co. (Fishing and Shocco creek subbasins), Nash
Co. (Stony and Swift creek subbasins, Tar River), Edgecombe Co.
(Swift Cr. Subbasin). NOTE: All headwater areas that flow into
these occupied habitats should receive special management.
Habitat Preferences
This species prefers clean, coarse to medium sized sands as
substrate. On occasion, specimens are also found in gravel substrates.
This species is found in the main channels of drainages down to
streams as small as a meter across.
Life History
Little is known of the life history of this species. Ortmann
(1914) found gravid females during
the spring in the James River, Virginia. Gravid females have been
found in the Tar River Basin in June . As verified by Tankersley
(1988), the glochidia are hookless.
Host fish have not been determined
for this species.
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