The southwest Gulf of California is the northern-most limit of fungiid (mushroom) corals in the tropical eastern Pacific, with two species present, Diaseris distorta and Cycloseris curvata. Fungiid corals are free-living, solitary animals that occupy sand and mud habitats throughout the tropical waters of the Red Sea, Indian and Pacific Oceans. However, there are few data on their biology and ecology, particularly in the widely scattered and small Eastern Pacific populations. This project will provide important details on their population distribution, density, live tissue cover, and coral size. Observations on species behavior and interactions (e.g. corallivory, feeding activity, etc.) will add to our understanding of this under-studied group. Data from two preliminary trips (June 2008, November 2009), documented relatively high population densities of living Diaseris near Isla Catalana (15.2 - 27.3 corals per m2), but details are lacking on other populations in other areas of the Gulf. Population data will be obtained through the use of 30 randomly located 0.25m2 photo quadrats (7.5m2 total area) at each site (Isla Catalana and new sites discovered during this research). Images will be processed using CPCe software and comparisons made using appropriate statistical tests (either parametric or non-parametric depending on data variance). In addition, the rare, endangered, endemic branching coral Porites sverdrupi will be included in the data collection. Further research on these corals will help clarify the factors that cause population changes providing important information for resource managers. Recent unparalleled declines in coral cover punctuate the need for faunal inventories, and information about the status of these coral populations will help determine if protection is warranted for this important resource.