DISTRIBUTION AND ABUNDANCE OF CHIONE CALI FORNIENSIS (PELECYPODA, VENERIDAE) IN THE ENSENADA DE LA-PAZ, BAJA-CALIFORNIA-SUR, MEXICO

The abundance and distribution of Chione californiensis in the interti dal zone of Ensenada de la Pat, B.C.S., is related to temperature, sal inity, dissolved oxygen, organic matter, and sediment granulometry. Th e distribution was affected mainly by sediment type, and the highest a bundance was observed in silt-sand sediments, changing gradually with the sediment. Abundance in this locality can be described by a parabol ic model considering sand as the independent variable if clay is not p resent. C. californiensis is the numerically dominant species on sandy and silt-sand bottoms.