REPAIRED SHELL DAMAGE AMONG SOFT-BOTTOM MOLLUSKS ON THE CONTINENTAL-SHELF AND UPPER SLOPE NORTH OF POINT CONCEPTION, CALIFORNIA

The frequencies of repaired shell damage were estimated for univalved mollusks on the inner and outer continental shelf and upper slope in the Santa Maria Basin, north of Point Conception, California. Twenty-one percent of all gastropods and 18.7% of all examined scaphopods had repaired shell damage. The frequency of repaired shells among prosobranchs was significantly lower at upper slope stations than at either inner or outer shelf stations. Conversely, the frequency of repaired shells among scaphopods was significantly greater at upper slope stations than at inner shelf stations. Opisthobranchs showed no significant depth-related differences in repaired shell damage. The frequencies of shell repairs varied considerably among taxa. For example, the frequency of repaired damage was high for a scaphopod, Cadulus tolmei (47.2%), and for a prosobranch, Alvinia rosana (24.3%), but was low for eulimid gastropods (7.6%) and three species of Epitonium (no repaired shells).