San Diego Natural History Museum--Your Nature ConnectionSDNHM Biodiversity Research Center of the Californias - Marine Invertebrates

Sourvenirs from the Sea



Western Winged Oyster, photo by Scott Rugh  Gorgonian photo   Cowrie, photo by Kevin Heard
Left: Western Winged Oyster, Pteria sterna (A.A. Gould, 1851) shell, found on San Onofre Beach
Center: California Golden Gorgonian, Muricea californica Aurivillius, 1931, photo © Tom Haight/www.oceanimages.com
Right: Live Chestnut Cowrie, Cypraea spadicea Swainson, 1823, with Strawberry Anemone, Corynactis californica Carlgren, 1936, in upper right hand corner

Rocky Offshore Bottoms support communities of invertebrates that are different from those found along the rocky shore. The Winged Oyster is a species that has been brought into our area from Mexico by El Nino conditions. The specimen pictured above was stranded on San Onofre Beach about two years ago. Gorgonian corals are among the exotic marine organisms that can be observed by divers. Shells of the Chestnut Cowrie are occasionaly washed up on southern California beaches.


Sandy Offshore Bottoms are the most prevalent shallow water habitat off the shores of southern California. The species of sandy bottom shells from 100 feet or deeper are generally different from those found along the shore. Beach replenishment operations in San Diego about a year ago brought the shells of these species on shore.

California Frog shells, growth series, photo by Kelvin Barwick  Western Bittersweet shells, photo by Kelvin Barwick Left: California Frog Shell, Bursa californica (Hinds, 1843) Shells, growth series, showing range in size of shells brought up by dredged sand used in beach replenishment, photo by Kelvin Barwick
Right: Western Bittersweet, Glycymeris septentrionalis (Middendorff, 1849) Shells, showing the variation of color patterns present in this species, photo by Kelvin Barwick
Text by Scott Rugh, Collections Manager, Invertebrate Fossils; photos by Scott Rugh and Kelvin Barwick