Besides the giant tube worms, which have so far been found only in the Pacific, there are pencil-size Jericho worms with accordion-like tubes; orange worms covered with tiny bristles; small benthic worms that wriggle through the mud; and finger-length, dark red palm worms that stand upright, topped with wig-like fronds. A special class of small worms, called Alvinellids , live on the walls of mineral deposits that form around vents.
Mussels, shrimp, clams, and crabs are abundant at many vents, but these are not the same species that you find in seafood dishes. The cocktail-size shrimp that dominate vents in the mid-Atlantic, for example, have no eyes. However, at least on species has an extremely sensitive receptor on its head that may be used to detect heat or even dim light coming from vents. Scientists still arent sure how shrimp and other vent creatures cope with chemical-laden seawater that would kill ordinary shellfish.
Biologists have observed a variety of smaller crustaceans around vents, including miniature lobsters called galatheids, and amphipods resembling sand fleas. They have also seen snail-like limpets the size of BBs, sea anemones, snakelike fish with bulging eyes, and even octopuses.
While octopuses are at the upper end of the vents food chain, bacteria are at the bottom. They are the first organisms to colonize newly formed vents, arriving in a snowlike flurry and then settling to form white mats or tendrils attached to the ocean floor. Bacteria have been found living beneath the oceans floor, and it seems likely that they emerge from below when the conditions are right. Vent bacteria can withstand higher temperatures than any other organism. That makes them attractive to researchers who are developing heat-stable enzymes for genetic engineering, and culturing bacteria designed to break down toxic waste.
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