Classification: State Endangered
NOTE: Hover over the bold words for definitions or see the Glossary.
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.
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.
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.
General Life History For Mussels
Conservation Plan for Five Rare Aquatic Species Restricted to the Neuse and Tar-Pamlico River Basins in North Carolina - 2020 (~6 MB PDF)