Annual spawning cycles and planktonic larvae of benthic invertebrates from Passamaquoddy Bay, New Brunswick

Abstract

Periods of larval occurrence are reported for 19 polychaete species and 10 other common planktonic larvae. Egg sizes are given for 29 polychaete species with estimates of spawning period for 14 of these based on studies of the adult worms. Spawning periods are shown to correlate better with larval type (e.g. whether planktotrophic or lecithotrophic) than with the zoogeographic distribution of the adults. Among the planktotrophic larvae, the evidence suggests that some larvae (e.g. polynoid larvae) develop successfully only during the spring diatom bloom, and gamete wastage may result from any substantial mismatch between the diatom bloom and spawning period. The lecithotrophic larva of the tunicate Boltenia ovifera, which spawns in midwinter, is described for the first time.