Septaria porcellana, the freshwater limpet. This diadromous snail was common on the faces of the waterfalls. It migrated further ipstream than all other neritids on Moorea. It had a strong grip too.
About one inch total length.
Empty weathered shell. Hardly see these.
Introduced to Bermuda along with Gonaxis sp. to control Otala lactea. They didn’t touch Otala lactea but instead targeted Bermuda’s endemic snail genus Poecilozonites, forcing the remaining species in the genus to near extinction.
LFNHC 2022-0023
Introduced species to Bermuda.
ID needed for the two on the left.
Edit: yes, alive!