RICE, A.; TSUKIMURA, B.; California State University, Fresno; California State University, Fresno: A Key To Brachyuran Zoea Of The San Francisco Bay Estuary

The purpose of this study was to examine and identify Brachyuran zoea of the San Francisco Bay Estuary, then to generate a dichotomous key. Zooplankton samples were obtained from the California Department of Fish and Game Neomysis plankton surveys and Clarke-Bumpus samples taken from five sites between San Pablo Bay and downstream Suisun Bay during April 2003-May 2004. The zoeae were separated into species using published literature, as well as Eriocheir sinensis reared in our laboratory. The zoeae were sorted according to different morphological features such as length of the telson, lateral carapace spines, midlateral spines on the abdomen, and the number of spines on each furca. Using the characters that remain consistent throughout all zoea stages, we devised a key to identify 13 species in the families Grapsidae, Xanthidae, Majidae, Cancridae and Pinnotheridae. Eriocheir sinensis was abundant February thru June. Cancer spp. were found throughout the year. Cancer productus was found June 2003 and February-May 2004. Carcinus maenas was found December-March. Hemigrapsus nudus and H. oregonensis were both found in February-March. Pinnotheridae were abundant throughout the year. Pyromaia tuberculata was abundant June thru December 2003 and again in May 2004. Cancer magister and Pachygrapsus crassipes are known to be present in the bay; however, they were not represented in the samples. Line drawings were made of species found in the samples. We think this will be a promising tool in research of zooplankton. This study was supported the National Sea Grant College Program of the U.S. Department of Commerce�s National Oceanographic and Atmospheric Administration under the NOAA Grant # NA06RG0142, and U.S. Fish and Wildlife Service.