Biodiversity and natural history of the opisthobranch Fauna at Bahia de los Angeles, Baja California, Mexico

Summary form only given. There are seasonal and yearly variations in the density and occurrence of opisthobranch molluscs at subtidal regions in this Sea of Cortes (Gulf of California) location. Data presented are based upon scuba assisted research over a 15 year span. New species are currently being described from this location, while other rare unnamed species are also known, but not yet able to be put into even a preliminary ms. form because of lack of sufficient specimens. Feeding specificity of some of these opisthobranch species will be illustrated. This research is especially important as baseline data that can be used in the establishment of a national park in the region.