Following the parasitism of the glochidia larval stage, juvenile and adult Texas hornshells consume algae, detritus, and bacteria through filter feeding.

[4] P. popeii may also use deposit-feeding methods to obtain food, such as using their muscular foot to attain edible particles from the river floor.

[10] They tend to live in the portions of the river where there are the fewest barriers that would prevent glochidia from finding suitable fish hosts upon release from the female brooding gills.

[10] These three species, C. carpio, M. congestum, and C. lutrensis, are parasitized by over 99% of P. popeii glochidia[10] and serve as the primary dispersal method for the freshwater mussel.

[15] P. popeii and various other freshwater mussels were previously more abundant in areas of the Rio Grande,[15] with 15 species living in the river system in the late 1990s.

[17] Additionally, the population size and area inhabited by P. popeii has drastically decreased, leaving only a 190-kilometre (120 mi) stretch of the Rio Grande that has a high abundance of P.

[10] The habitats of Texas hornshells, desert aquatic ecosystems, are highly susceptible to the major causes of biodiversity reduction seen globally.

Fish and Wildlife Service's endangered classification of P. popeii is accompanied by federal protection, more research efforts are still being carried out to investigate key factors that may be useful in developing effective mitigation plans.

[11] If not properly handled, it is predicted that distribution of P. popeii will not increase as potential habitats are altered or removed by human activity.