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Resources to our amazing natural world

Tide pools occur in rocky shore locations where the ocean meets the land. A whole host of fascinating plants and animals survive in this rugged, changing seascape. As the ocean water retreats at low tide, marine life must withstand hours exposed to the air or in shallow pools. At high tide, animals and plants must survive waves rolling in or crashing down. Pictured right are two invertebrates most commonly spotted in tide pool habitats, green anemones and purple urchins.

The adult giant green anemone attaches to a substrate and rarely moves. Although it gets some of its green color through natural pigmentation, much of its color is gained from the symbiotic relationship it has with the micro-algae and dinoflagellates that live in its tissues. These unicellular organisms are photosynthetic, providing the giant green anemone with beneficial nutrients as well as pigmentation. 

A purple sea urchin's pincushion appearance comes from its round inner shell, called a "test." The radially symmetrical  test is covered with pincer, tube feet and purple spines that move on ball-and-socket joints. The spines spear food and protect an urchin from predators. Tiny hairs (cilia) covering the spines create a water current that carries food to the urchin and washes away wastes.