Metamorphosis in a Sea Snail
In a way that is analogous to what happens when a caterpillar becomes a butterfly, the change in lifestyle from a pelagic (open-water dweller) larva to a bottom-living adult is also known as metamorphosis. The illustration presents three shell-growth stages of an Atlantic Gray Cowrie, Luria cinerea (Gmelin, 1791). From left: the planktonic (free-living) larval shell; juvenile shell briefly after settlement to the bottom-living stage; and adult shell. They are all so different, yet all are stages in the development of the same species. The natural color in the two leftmost images was hidden by the imaging process, scanning electron microscopy. The larval shell on left is clear as glass, with a golden-yellow tinge! Scale bars are 0.5 mm for the larval and juvenile shells and 10 mm for the adult shell (0.5 mm = 0.02 inch; 10 mm = 0.4 inch).