Capelin (Mallotus villosus) spawning behaviour in Newfoundland waters -: the interaction between beach and demersal spawning

In Newfoundland, Canada, capelin, Mallotus villosus (Muller), predominantly spawn intertidally on gravel beaches, but demersal spawning in coastal waters adjacent to spawning beaches has been reported. Demersal spawning is hypothesized to occur after the completion of intertidal spawning, when beach water temperatures become too warm for spawning. We present results from a study of capelin spawning and egg development in a single major spawning location that reject this hypothesis. In 2000, some demersal spawning took place simultaneously to beach spawning, the choice of spawning location being dictated primarily by water temperature. Our results indicate that beach spawning is the preferred option. Peak spawning dates during the past decade were in July, approximately four weeks later than during the 1980s. Demersal spawning was common during the 1990s. In 2000, larval emergence from demersal spawning sites was negligible. We discuss the implications of demersal spawning to overall reproductive success when spawning is delayed. Crown Copyright (C) 2002 Published by Elsevier Science Ltd on behalf of International Council for the Exploration of the Sea. All rights reserved.