Barnacles

There are over 2000 species of barnacles, most of which live in shallow waters and tidal zones. Barnacles, believe it or not, are crustaceans, related to crabs, lobsters, and shrimps. They don't have legs, unlike their cousins, but stick to rocks and other hard surfaces like boats, whales, and shells. Once in their new home, barancles usually stay there for the rest of their lives, filter feeding plankton and other particles from the water.

Barnacles are mobile as juveniles, but become sessile (organisms that lack the ability of self-locomotion) as adults. Thus, by attaching themselves to other organisms - such as the crab in the photos below - they can move to a new area, thus potentially giving them better access to food and protection from predators.

  • An Acorn Barnacle
  • Marine organisms often take advantage of the bounty of the ocean. In this case, a set of barnacles has attached themselves to an empty clamshell.
  • Barnacles have attached themselves to this swimming crab, as has an immature scallop.
  • A closer look at the barnacles on this swimming crab.