Growth, seasonality, and dispersion of a population of Aplysia vaccaria Winkler, 1955

The growth and spatial dispersion of an intertidal population of the Califo rnia black sea hare, Aplysia vaccaria Winkler, 1955, was studied from Octob er 1995 to October 1996 in North Cardiff Beach, California. Population size peaked in November and then declined to zero the following year, while mea n weight peaked in June. Breeding was observed throughout the year. The sea hares were spatially clustered and the aggregation pattern was invariant o ver time. Individual movements and growth were recorded by tagging 19 anima ls with internal microchips. Tagged animals grew at a rate of 4.9 g/day and moved an average minimum distance of 2.3 m/day.