THE INFLUENCE OF TEMPERATURE ON THE SURVIVAL, GROWTH AND RESPIRATION OF CALANUS FINMARCHICUS

Abstract

Laboratory tests on cultures of Calanus in relation to the ecology of this species showed that: (a) removal of the culture dishes from constant low temp. to room temp. for daily periods as great as 120 min. was not harmful to the copepods; (b) growth was poorer at 3[degree]C than at 6 to 9[degree]C, but survival was better at the lower temp.; (c) both growth and survival decreased regularly in passing from expts. conducted in the spring to those in the autumn. Measurements of the respiration of Calanus using the Winkler method and the Dixon-Haldane respi-rometer showed that the magnitude of the O2 requirement for these animals is of the same order as for those tested by Marshall, Nicholls, and Orr, and possibly is higher than previously reported. The discrepancy between the estimated food requirement of Calanus and the average abundance of diatoms therefore still exists but certain possible explanations are discussed.