Before this area was settled in the 1700s, it is likely that this species occurred in many large waterways within the Tar and Neuse river basins.

[5] The range of the Tar River spinymussel is very restricted which indicates that the suitable habitat for this species is limited.

[5] The Tar River spinymussel is mostly found in loose beds of coarse sand and gravel.

[7] Surveys done by the North Carolina Wildlife Resources Commission from 2014-2020 found only 11 individuals over the course of high-sampling efforts.

[9] The fact that females release conglutinates multiple times during one brooding season makes the Tar River spinymussel iteroparous.

[5] The closely related and also endangered James River spinymussel has a comparable life history.

[7] The Tar River spinymussel, makes conglutinates which are filled with glochidia, the larvae of a mussel.

[12] When this species reproduces, females of the Tar River spinymussel can release up to four to five times the amount of conglutinates.

Additionally, more suspended sediment leads to less light penetrating the water column which decreases phytoplankton abundance.

Runoff water from agriculture, residence, and construction sites contain chemical pollutants that are a major threat to the extant populations.

Reducing the number of large trees that maintain the stability of the stream and river banks degrades the spinymussel’s habitat.

Wastewater effluent can introduce toxic chemicals, diseases, and microplastic pollutants into the habitat of Tar River spinymussels.

[2] The five-year review for the Tar River spinymussel was initiated in the Federal Registrar on June 20, 2019.

Declining numbers as well as the previous threats mentioned indicate that the Tar River spinymussel still meets the definition of endangered.

In 1985, the reasons for listing included habitat modification/destruction, over-utilization, disease/predation, lack of regulatory mechanisms, and exotic species.