As you walk along the beach you'll often find the big brown seaweed called kelp. Look closely at kelp blades, and you may spot a thin, white, crusty patch patterned like fine lacework. This is the Kelp Lace Bryozoan - a colony of thousands of microscopic animals called zooids. These zooids live in tiny box-like houses made partly of calcium carbonate, the same material as shells. From each zooid box minute tentacles reach upward. Bryozoans are filter feeders; they flick these tentacles through the water, catching bits of algae and bacteria.

Though tiny, these kelp lace animals are quite complex. They have several sets of muscles, special ones! One set pulls the animal into its box; another seals the box shut. The tiny zooid even has a simple nervous system.

When bryozoans reproduce, they send out larvae that swim by opening and closing their shells like little umbrellas. When the larva finds a clean kelp blade, it parachutes down through the water and attaches itself with sticky glue. As the bryozoan grows and reproduces, the new colony radiates outward to form a circular patch over three inches in diameter. The colony is firm but flexes with the kelp's waving movements.

By living on kelp this bryozoan avoids many predators. Some still fall prey to sea slugs or fish. Others are destroyed when sea urchins graze the kelp.

Bryozoans produce many chemical compounds which scientists are studying for possible medical use. A healthy ocean could mean a healthier you!