Interactions between two infaunal bivalves, Chione undatella (Sowerby) and Protothaca staminea (Conrad), and two potential enemies, Crepidula onyx sowerby and Cancer anthonyi (Rathbun)

摘要: Abstract Crepidula onyx Sowerby occurred on ≈ 1% of Chione undatella (Sowerby) and no Protothaca staminea (Conrad), collected in June 1975 from a California Zostera marina L. meadow. All were measured returned at systematically varied densities to field enclosures. During the following two years, showed preferential colonization , while remained free epibionts. Successful recruitment individual was > 100 times more intense already occupied hosts, suggesting gregarious settlement behavior. Colonization previously unoccupied did not vary significantly among enclosures as function host ( ) density (6–48 · m −2 spread new hosts contagious. Growth, but survival, carrying less than that perhaps reflecting interspecific competition for suspended foods. Collections crushed shells inside cages by predator Cancer anthonyi (Rathbun) indicate this crab preyed upon thin-shelled epifauna preference infaunal molluscs. Despite its slightly deeper burial, thicker-shelled often found crushed. In response other predators, had much lower annual survival during both years. may select because shallower depth burial allow efficient suspension-feeding attached . Alternatively, if prefers greater longevity, then 's successful defense against predators indirectly contributes susceptibility