The life cycle of Callianassa californiensis Dana, 1854, was studied in the tidal estuary, Yaquina Bay, Oregon. At this latitude it is largely restricted to intertidal sandy mudflats under predominately marine influence. Salinity and temperature appear to determine its distribution to a greater extent than does sediment type. Vertical movement within the sediment is related to the tides on a day to day basis and to temperature on a seasonal basis. Large-scale breeding generally begins in the spring, and ovigerous females may be plentiful in the cooler layers of mud until August. It is not clear what triggers larval release, but temperature and tidal conditions seem to be important. All five zoeal stages are found in the plankton from the mouth of the bay to three miles offshore during late spring and summer. Nearshore waters appear to act as a larval reservoir along this part of the coast, and successful larval settlement may depend upon high-tide transport into a bay. / Graduation date: 1972

Graduation date: 1967