ISSN:
1432-1793
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract Seasonal occurrence, individual growth and development of population biomass of the scyphomedusa Aurelia aurita were studied in 1978–1979 in the western Baltic Sea. First ephyrae of the developing population appear in November, but the great majority are produced in April and May. On the average 0.09 medusae m-3 with a biomass of 25 g occur between July and September. The standing stock is below 10 mg from December to April. Growth is characterized by a stagnation period in winter and early spring, by rapid increase in early summer and by size reduction in autumn after release of gonadal products. The maximum monthly growth rate was observed in June, when the average diameter increased from 7 to 48 mm and the wet weight from 0.06 to 22.8 g. Mortality is low before maturation. Genetical determination, starvation and parasitization are discussed as causes for morphological reductions and finally for death in autumn.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00389155
