EFFECTS OF FOLIACEOUS VARICES ON THE MECHANICAL-PROPERTIES OF CHICOREUS-DILECTUS (GASTROPODA, MURICIDAE)

Removal of the foliaceous varices from the shells of Chicoreus dilectu s had no significant effect on the crushing strength (load at failure) of the shells, but decreased the total work necessary to break the sh ells by 35-50%. This effect was due to the removal of varices as an ar chitectural feature of the shell rather than simply to the removal of shell material pet se; varicate shells had a mean work to failure per unit shell mass 1.6-2.3 times greater than avaricate shells. Because t he strength of gastropod shells often exceeds the maximum forces that durophagous predators may bring to bear on them, work to failure may b e a more important factor in the design of gastropod shells than break ing load.