Published online by Cambridge University Press: 11 June 2012
In the course of our studies of reproduction of Calanus finmarchicus under laboratory conditions we noticed that all the eggs produced in our cultures were lying on the bottom of the glass dishes, and when transferred into fresh culture medium (“Erdschreiber”) or sea-water sank down relatively very rapidly. As the eggs were fertilised and healthy, and a large proportion of them developed into active nauplii (Raymont and Gross, 1942), it was obvious that the density of the living egg was considerably higher than that of sea-water.