Reproductive effort in molluscs.

A survey of the available molluscan literature shows that reproductive effort is higher in semelparous species (29.90%) than in iteroparous species (18.21%), and that in iteroparous species reproductive effort increases with successive breeding seasons. Oviparous species were found to divert considerably more into reproduction than viviparous species, with 24.24% and 5.25% channeled respectively.