The Comb Bittersweet, Tucetona pectinata (Gmelin, 1791), is found along the coast of Southwest Florida. Bittersweet clams have numerous, simple eyes that resemble the ommatidia, or the individual units, of insect eyes. They can be seen as tiny dark dots along the mantle edges of the Comb Bittersweet in the photo. Studies on the eyes of bittersweet bivalves (family Glycymeridae) suggest that they can be used to sense approaching predators by sudden changes in light intensity (the “shadow reflex”) and/or by detecting their movement. Read more about mollusks and their shells at the Museum's Shell Guide.