The classification of the Atlantic Slope species of Elliptio is currently in a state of uncertainty. This research is in progress and will result in the recognition of numerous additional taxa in this genus. Johnson (1970) considered Elliptio roanokensis a synonym of Elliptio complanata. E. roanokensis is a distinct, large freshwater mussel with branched papillae. NC Wildlife Resources Commission (NCWRC) field experience indicates that what had been called Elliptio judithae from the Neuse drainage is a synonym of Elliptio roanokensis. This view has been tentatively supported by other malacologists (Art Bogan, North Carolina State Museum; John Alderman, North Carolina Resource Commission) based on conchological and soft-tissue features. Clarke (1986) described Elliptio judithae from the Neuse River, but his description of the species matched that of smaller individuals of Elliptio roanokensis (Adams et al. 1990).

A list of synonyms for this species can be found on The MUSSEL project web site (Graf and Cummings 2011).

Elliptio roanokensis has been assessed as Vulnerable under criterion A2ac. Historical ranges have probably reduced by up to half over the last 25-50 years, but no definitive studies have been undertaken. Some populations appear large; however, they are probably significantly reduced from historical levels. Most populations are still declining in abundance. Few signs of recent reproduction are seen in most North Carolina and South Carolina populations. The Cape Fear River population has significantly declined since the mid-1970s. Recent collections in the Great Pee Dee River in South Carolina are all dominated by older individuals and few at that indicating low recruitment (Catena Group 2006). Using a precautionary approach, we assume that a range decline of 50% over the timespan of 25-50 years translates into around 30% decline in populations over the same time-frame, which approximately covers three generations based on estimates from life history characteristics of other species in the genus. It is vital that additional data are collected on life history and population declines to verify the assumptions made in this assessment.

It has not been previously listed, as the evidence was considered marginal as a candidate, based on the data available in 1996 (Bogan and Seddon, pers. comm., 2012).

The global range includes major Atlantic Slope river basins from the Chowan River Basin in Virginia to the Savannah River Basin in Georgia and South Carolina (including Pee Dee, Congaree, and Savannah, but the species is absent from many others). Recently, it was found at thirteen sites in the Pee Dee River drainage in South Carolina (Catena Group 2006), extending its range into the Great Pee Dee River.

This species is extant at the type locality in the Roanoke River, North Carolina (A. Bogan pers. comm. 2010).

The Roanoke Slabshell was probably an abundant, dominant mussel species within its historical range during past centuries. The Roanoke and Chowan populations are nearly extirpated. The Tar, Neuse, Cape Fear, and Pee Dee populations have significantly reduced ranges and appear to have few signs of recent reproduction. Little is known of the Cooper-Santee population. The Savannah River population also has a significantly reduced range; however, the population still appears healthy. Populations in tributary creeks and rivers exist in the Tar, Neuse, Cape Fear, Pee Dee, Cooper-Santee, and Savannah river basins (Bogan 2002); however, most are vulnerable to extirpation. Bogan and Alderman (2004) list the South Carolina distribution as in the Cooper-Santee and Pee Dee River systems and in the Savannah River basin. It was recently found at thirteen sites in the Pee Dee River drainage in South Carolina, all in the Great Pee Dee River (Catena Group 2006); this extends the range into Great Pee Dee River. LeGrand et al. (2006) list the Cape Fear north to Roanoke River systems in North Carolina (Anson, Bladen, Carven, Cumberland, Edgecombe, Halifax, Harnett, Johnston, Montgomery, Nash, Northampson, Pitt, Randolph, Richmond, Stanly, Wake, Wayne Cos.). Alderman (2006) recorded a few sites on the Congaree drainage in South Carolina.

It is common in several sites in the Pee Dee, Savannah and Congaree Rivers and is nearly extirpated from the Chowah and Roanoke Rivers. The main-channel Tar, Neuse, Cape Fear, and Pee Dee populations probably exceed 100,000 individuals. The main-channel Savannah population probably exceeds 500,000 individuals. Recent collections in the Great Pee Dee River in South Carolina are all dominated by older individuals indicating low recruitment (Catena Group 2006).

Historical ranges are probably reduced by up to half over the last 25-50 years, but no definitive studies have been undertaken. Some populations appear large; however, they are probably significantly reduced from historical levels. Most populations are still declining in abundance. Few signs of recent reproduction are seen in most North Carolina and South Carolina populations. The Cape Fear River population has significantly declined since the mid-1970s.

Tributary creeks and rivers occasionally provide significant habitat. The best populations occur where anadromous fish (probable primary fish hosts) have access to lotic habitats. Small or declining populations may be found above dams and their associated reservoirs which serve as barriers to anadromous fish. (It is assumed that less appropriate secondary fish hosts may occur in such areas.) Presently, this species is usually found in near-shore trough habitats in sand / gravel substrates. It may also be found in more coarse substrates. In the Pee Dee River drainage in South Carolina, it was usually found in deep run habitats dominated by coarse sand/pea gravel, and fairly swift flow. It was most commonly associated with the Carolina lance and Carolina slabshell (Catena Group 2006).

Direct life-history data are not available for this species. Freshwater mussels are highly variable in their longevity from species to species (e.g. Haag and Rypel 2011). Studies have shown longevity of Elliptio species to range from 14 to 57 years (from populations of E. arca, E. complanata and E. crassidens: average of 30 years; Haag and Rypel 2011). Even longer lifespans have been recorded for other species of Elliptio (e.g. 75 years, Elliptio complanata; Anthony et al. 2001). Ellipto arca was found to mature at two years of age (Haag and Staton 2003). Conservatively assuming a first age of maturity of between 2-5 years, generation length (estimated as the average age of a parent in the population, and based on lower and upper age estimates given in Haag and Rypel (2011)) is estimated as around 8-31 years, with three generations spanninng around 24 to more than 90 years. However, the lower estimates may represent a vast underestimate of generation length, as it has been suggested that growth ring counts may underestimate age by a factor of between three and ten (Anthony et al. 2001).

Threats to this species probably include habitat degradation as a result of water abstraction from dams and associated reservoirs, and channel modification. Sedimentation and numerous point and nonpoint sources of pollution are potential threats. Sampling probably has little impact on populations. In-stream mining or dredging would also have significant impacts on local populations. This species is mostly a big-river riffle species. Therefore, there are numerous impacts to the species' habitats; thus, it is very difficult to affect habitat improvements.

This species is not utilized.

This species has been assigned a NatureServe Global Heritage Status Rank of G3 - Vulnerable, and a State/Province Status Rank of S2 - Imperiled for Georgia and South Carolina, and S1 - Critically Imperiled for North Carolina and Virginia (NatureServe 2009).  Williams et al. (2010) list this species as Vulnerable according to the AFS assessment. No widespread conservation actions have been undertaken. Further research regarding taxonomy, population trends and life history, accompanied by monitoring of population trends, will help elicit future conservation strategies in response to changes in population status. There is also a need for structured site protection and enforcement to uphold protection of this species.