Gene flow in reef fishes along the California and Baja California coasts

Giacomo Bernardi, Ph.D.
University of California, Santa Cruz

Wednesday, February 9, 2000
3:00 p.m.—Pacific Forum

Three major biogeographic breaks that separate marine species assemblages have been described along the California and Baja California coasts. These breaks are Point Conception, Punta Eugenia, and Cabo San Lucas. Are these breaks effective barriers to gene flow at the population level as well? We have used molecular tools to determine the levels of gene flow across these biogeographic breaks for populations belonging to several fish species that exhibit different degrees of dispersal capabilities. We found that Punta Eugenia and Cabo San Lucas are in most cases effective barriers to gene flow. In contrast, Point Conception was not found to be a barrier to gene flow. Unexpectedly, the large sandy stretch at Santa Monica Bay was found to be a very effective barrier to dispersal in black surfperch. Ecological and evolutionary implications will be discussed.

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 Last updated: December 19, 2000