Fortuin a w de wolf l (1 risultati)

The population structure and life cycle of A. grayana are described, based on size frequency-distribution histograms of samples from a salt-marsh along the Western Scheldt estuary. Generations of previous years could be distinguished until June; later on they merged to form one inseparable group. Highest numbers were found in winter. Numbers decreased at the end of the winter, mainly due to mortality, and in spring, mainly due to migration. First representatives of the new generation were found in July. In Oct. the main part of the population consisted of this new generation. At least part of the individuals may live for two years. 6 pp., 3 figs, gr. 8. …