The Cayenne keyhole limpet is found from New Jersey south through the West Indies to Brazil; in the Gulf of Mexico and in the Caribbean Sea; off the Canary Islands.

[5] This species of limpet lives in inlets and offshore waters attached to rocks or shells and is occasionally found on sponges,[5] as well as washed up on sound and ocean beaches.

[8] Its powerful foot creates strong suction to keep waves from washing it off the rocks in intertidal and shallow subtidal areas.

Diodora cayenensis primarily feeds on algae, using its radula to scrape these organisms off surfaces such as rocks and coral.

[10] The Cayenne keyhole limpet reproduces via broadcast spawning, a form of external sexual reproduction typically done by sessile organisms.

Because intertidal zones are a constantly changing environment, D. cayenensis release large quantities of eggs into the water in order to increase fertilization rates[11] and in turn the number of offspring.

As a reproductive strategy, broadcast spawning relies heavily on turbulent stirring processes in the flow to bring together compatible gametes for fertilization to happen.