THE OOGENIC CYCLE OF NEREIS-DIVERSICOLOR UNDER NATURAL CONDITIONS

Two recent descriptions of the life cycle of N. diversicolor from different estuaries in Britain show close similarities in population structure, growth rate, size at maturity and time of breeding between the populations. Important differences occur in the oogenic cycle. Worms from the Severn Estuary mature rapidly in spring and most spawn at 2 yr old, but females from the Blyth Estuary mature over the winter months and most probably spawn after 3 yr.