On the Biology of Calanus finmarchicus. V. Seasonal Distribution, Size, Weight and Chemical Composition in Loch Striven in 1933, and their Relation to the Phytoplankton

Abstract

1. The seasonal changes in the population of Calanus in Loch Striven in 1933 have been investigated.2. There were three main breeding periods. The first was in February and March, an unsuccessful beginning of the second in April, the true second brood in May to June, the third in July, and subsidiary broods in August and September.3. Numbers were very low until April when the copepodites of the first brood caused a large increase; there was a second increase in May consisting mainly of the eggs of the second brood, and the maximum for the year came in July. The last and subsidiary broods provided the stock for the autumn and winter of 1933.