Clams and mussels are filter feeders, filtering out microscopic plants and animals floating in the water. Clams move about by using a hatchet-shaped foot to creep along the muddy bottom of the Bay. The sticky threads are produced from a gland near their foot. Phylum Annelida Invertebrates in the Phylum Annelida are segmented worms. A common bay inhabitant in this group is the tube worm.
Tube worms live in brown mud tubes that the worms make from a mucus and mud mixture.
The tube worm is not native to San Francisco Bay, it was introduced in the 1800's with the oysters brought over from the east coast to start an oyster industry in the Bay. Phylum Arthropoda Invertebrates in the Phylum Arthropoda have jointed limbs. Common bay inhabitants in this group include crabs, crayfish, insects, and spiders. The decorator crab is an arthropod that we often see on MSI's Discovery Voyages. The decorator crab uses its front claws to eat algae and other dead plant or animal life from the bottom of the Bay.