Adaptations of Shellfish

Strong Feet

• Many shellfish such as some clam and oyster species live in shallow water that is subjected to strong currents. In order to prevent themselves from drifting away with the tides, mollusks have a muscular foot that will poke out of its shell and dig in the sand to hold them in place. Other creatures that live in similar environments such as starfish have also adapted ways to stay put in heavy tides.

Thick Shells

• According to the Unites States Army Environmental Laboratory, fresh water mussels that have adapted to have thicker shells are much more hardy than thinner-shelled mussels. Thinner-shelled mussels are more susceptible to being injured when handled, moved or jostled around. This is a useful adaptation for humans too, because it prevents loss of product when shipping and handling mussels for human consumption.

Feeding Methods

• Most shellfish live at the bottom of bodies of water, and have adapted to eat food they find along the sea floor or river bottom. For example, oysters and clams have adapted special gills that filter food particles from the water for them to eat. Lobsters have poor eyesight and instead use specially adapted antennae to find food on the ocean floor.

Movement

• One adaptation of the crab is that it walks sideways because the shape of its legs makes it difficult to walk forward. This makes the crab move much faster underwater, allowing it to flee from predators. Even seemingly stationary shellfish, such as scallops, have adapted to move quickly through the water. Scallops do this by opening and closing their shell very fast to propel themselves through the water.