Fish Bulletin No. 18. The Pismo Clam : Further Studies of its Life History
On the open sandy beaches of California there is found a large heavy-shelled clam, Tivela stultorum (Mawe), commonly known as the Pismo clam. This clam thrives only on the exposed beaches subject to the constant washing and pounding of the surf and if transplanted to sheltered water where the active surf is absent will soon die. Tivela occurs on nearly all the favorable beaches from Half Moon Bay in the north, where a few specimens are found, to Socorro Island, Lower California, in the south. At Monterey Bay it is found in sufficient numbers to support a considerable commercial fishery, especially near Moss Landing, but the clams are found so far out in the surf that they are usually dug only by experienced clammers during the low tides. On the beaches of San Luis Obispo County at Pismo, Oceano and Morro, Tivela is at present found in the greatest abundance north of Lower California. Practically the entire commercial catch shown by the records of the Division of Fish and Game of California comes from this region. Farther south, at Long Beach and Anaheim Landing, the Pismo clam was formerly abundant, but is at present only occasionally found. On the coast of Lower California it is reported by fishermen to occur in some places in great numbers, and small amounts have occasionally been brought into southern California ports from Turtle Bay by some of the fishing boats.