RESTING EGGS OF ZOOPLANKTON (COPEPODA AND CLADOCERA) FROM THE KIEL-BAY AND ADJACENT WATERS (SOUTHWESTERN BALTIC)

Resting eggs of four species of calanoid copepods and three species of cladocerans were collected from sediments up to 5 cm depth from the K iel Bay and adjacent waters in the southwestern Baltic Sea during Apri l-May 1994. All but one species of cladoceran was successfully hatched /reared in the laboratory. In the Kiel Bay, egg abundances varied from 1.8 x 10(5) to 7.4 x 10(5) m(-2). Hatching success of copepod eggs co llected from all depths was high (49 to 94%), but was 0 to 79% for cla doceran eggs; Darkness did not seem to affect hatching. Eggs found in the 4 to 5 cm layer of sediment were estimated to be about 15 yr old, showing the presence of an ''egg bank'' in the Baltic. Formation of re sting eggs may be a genetic trait acquired during the ice ages.