FEASIBILITY OF INCUBATION EXPERIMENTS TO ESTIMATE MOLTING RATES IN MARINE COPEPODS

Moulting rate estimates of Temora longicornis and Pseudocalanus elonga tus in short incubation experiments in the laboratory were compared wi th shipboard experiments in the North Sea. Absence of food, rotation o f bottles and (an extremely small) container size did not affect the m oulting rate in well-fed copepods. A minor bias was found due to gentl e handling. High variance was due to the use of different samples, one before and one after incubation, which is part of the so-called 'Kimm erer method'. This error can be reduced by monitoring the new producti on of exuviae in a single sample, which makes sorting of individuals u nnecessary, while conserving the estimate of moulting rate in individu al stages.