Definition
'Diodora apertura' is a species of keyhole limpet, a marine snail with a hole at the apex of its shell. They cling to rocks in shallow waters. This opening serves as a vent for respiration and waste. They are herbivores, grazing on algae. Think of them as tiny, shelled underwater filters. They're not the flashiest snails, but they get the job done. The shell shape is slightly elongated. It is commonly found in European waters.