On the biology ofCalanus finmarchicusVIII. Food uptake, assimilation and excretion in adult and Stage VCalanus

Apart from a few scattered observations (Hensen, 1887; Gran, 1902) the study of the food of Calanus began with Dakin (1908). He examined the remains present in the gut, and this was the method used also by Esterly (1916), Lebour (1922) and Marshall (1924). They all found that these remains consisted of a greenish mush containing the skeletons of numerous planktonic organisms, chiefly diatoms and dinoflagellates. Naked flagellates were, how-ever, occasionally seen, and it was realized that the food might in reality consist largely of organisms which had no skeleton and could leave no recognizable remains.