#unionoida

Freshwater pearl mussel - Wikipedia

Snuffbox (Epioblasma triquetra)

...an endangered species of freshwater Unionid bivalve which is distributed throughout the Great Lakes and Mississippi Systems in North America, ranging from western New York and southern Ontario, west to Wisconsin, Iowa, and eastern Nebraska, south to Oklahoma, and east to northern Alabama. Snuffboxes typically occur in small to medium sized rivers, but are known to inhabit streams as well. 

Snuffboxes are most well known for their reproduction strategy. Unlike most Unionids which use lures to get fish close, snuffboxes are more direct. The primary host of the snuffbox is the Common Logperch (Percina caprodes) which forages by turning over rocks to feed on whatever is seeking refuge under them. To get logperches to ingest their larvae female snuffboxes camouflage themselves and rocks and when a logperch attempts to flip one, she will quickly clamp onto the head of the logperch and directly pump her glochidia into the logperches gills. This strategy will only work with logperches as they have a thick enough skull to not get crushed when they get clamped!

Classification

Animalia-Mollusca-Bivalvia-Palaeoheterodonta-Unionoida-Unionidae-Epioblasma-E. triquetra

Rayed Cakeshell (Anodontoides radiatus)

...a species of freshwater Unionid bivalve which is known to occur in Georgia, Alabama, and Mississippi, Louisiana, and Florida in the United States. In this range Anodontoides radiatus occurs in isolated and fragmented areas. Despite this A. radiatus is still widespread and "only" listed as Near Threatened. Rayed cakeshells are typically known to inhabit large rivers, but they will also medium-sized creeks as well.

Classification

Animalia-Mollusca-Bivalvia-Palaeoheteodonta-Unionoida-Unionidae-Anodontoides-A. radiatus