Biology of the Lucky Strike hydrothermal field

Abstract-Newly discovered hydrothermal vent communities at Lucky Strike on the Mid-Atlantic Ridge (37”18’N, 32”16’W) are comprised of an invertebrate fauna sufficiently different from known vent faunas of TAG and Snake Pit to consider Lucky Strike part of a new biogeographic province. The dominant component of the fauna is a new species ofmussel, and the most unusual feature of the fauna is an echinoid echinoderm, Echinus sp. An abundance of small mussels (< 5 mm) indicates a recent recruitment event at Lucky Strike, and modal analysis of length-frequency data indicate