This conical shape and the low profile of the shell allow keyhole limpets to withstand wave attack on exposed rocks to which they attach firmly with their strong, muscular foot.

This opening at the top allows a direct exit of exhalant water currents together with waste products from the mantle cavity.

Most young species in this family have a marginal slit in the middle of the anterior end of the spiral shell.

This foot exerts a strong suction, adhering the keyhole limpet to its hard substratum.

[5] In addition to the possession of this hole, slit or groove, keyhole limpets differ in several other ways both internally and externally from true limpets.[how?]

They play an important role in marine ecosystems by controlling the growth of algae on rocky substrates.

Family Fissurellidae Fleming, 1822 This classification was based by Bouchet & Rocroi on the studies by Keen (in Moore) (1960), Christiaens (1973) [7] and McMean (1984).