Because hydrothermal vents cover many different areas, depths, and latitudes, the community structure differs considerably (Gage and Tyler 1990).  For example, the better studied and more diverse Pacific fauna on a spreading center differs from an Atlantic fauna on a spreading center.  Specifically, abundant mollusks and tube worms around hydrothermal vents in the Pacific are either rare or absent in the Atlantic(Gage and Tyler 1990) .  However, all hydothermal vent communities have community similarities.  Typically, sulfur-oxidizing bacteria, a community in its own right, make up the primary producers (Gage and Tyler 1990) .  Not much is known about these bacteria.  Moreover, the same bacteria that live freely around the vents also live within some of the invertebrates as endosymbionts.  Endosymbiotic invertebrates include snails, clams, and worms.  The macrofauna consists of the more typical oceanic creatures including crustaceans, shrimp, and rare fishes.     
           The better known Pacific fauna includes a richer macrofauna component including a variety of worms, crustaceans, mussels, anemones, tubeworms, and plumes of zooplankton that swarm above the hydrothermal vents. (Gage and Tyler 1990).