Keyhole Limpet
Keyhole Limpets (Fissurellidae spp.)

The Keyhole Limpet uses a small hole on top of its shell to push out waste and used water. Fresh water flows in from under the edge of the shell. It uses a tongue-like part called a radula to scrape algae and thin layers of slime and microorganisms from rocks and other hard surfaces.
There are several different species of Keyhole Limpets on Bonaire, and it can be hard to identify them because there is not much information available. They are mostly seen in shallow areas, especially on pier pillars or rocks in the tidal zone.