Barnacles

Because barnacle buildup on the bottom of boats costs boat owners substantial sums, scientists continue to study the ways in which barnacles attach themselves to objects. To date, they have learned that barnacle larvae search for a permanent home and when chosen, they secrete a glue like protein to attach themselves and send a signal inviting other barnacles to join the colony.

Afterward, they develop into adults, growing their shell like bodies, and living out their lives.

Being encrusted in small shells suggests that the animals belong to the mollusk phyla. However, they actually constitute an entire Subclass of Crustaceans (Cirripedia) in the Arthropod phyla. In effect, spiders are crabs, not snails, are among their closest relatives.

The picture shows an up close view of a group of barnacles. The two flat plates inside the shell open and close, allowing the barnacle to send out its tentacles to collect the small organic material, such as algae, floating nearby.

© 2009 Patricia A. Michaels