Spatial and Temporal Population Genetics at Deep-Sea Hydrothermal Vents Along the East Pacific Rise and Galapagos Rift

摘要

Ecological processes at deep-sea hydrothermal vents on fast- spreading mid-ocean ridges are punctuated by frequent physical disturbance. Larval dispersal among disjunct vent sites facilitates the persistence of sessile invertebrate species in these geologically and chemically dynamic habitats despite local extinction events. Regional population extension and rapid recolonization by the siboglinid tubeworm Rifliapachyptila have been well documented along the East Pacific Rise and the Galapagos Rift. To analyze spatial and temporal population genetic patterns and the processes governing them at ephemeral and disjunct habitats, a suite of 12 highly variable microsatellite DNA markers were developed for this species. Eight of these loci were used to assess the regional and within-ridge genetic structure of recent colonists and resident adults collected from nine sites in the eastern Pacific Ocean over period of three to seven years. A significant seafloor eruption during the seven-year sampling period allowed investigation into the role of local extinction in population genetic diversity at the Tica vent site at 9 deg N EPR, while collections within two and five years of an eruption that created the Rosebud vent field at 86 deg W GAR provided insights into genetic diversity input over population establishment.