HYDROTHERMAL VENT COMMUNITIES AND PLATE-TECTONICS

Deep in the oceans, hydrothermal vents are home to an extraordinary ar ray of fauna, These animals depend primarily not on sunlight, but on t he chemical energy of the hot fluids issuing from the cracked volcanic rocks along the mid-ocean ridges, Of the 442 species so far discovere d? only 9% are known to occur elsewhere, Regional similarities in the distribution of this fauna seem to be controlled by the distance betwe en vents along the mid-ocean ridge system and by the history of the te ctonic development of the ridges.