The effect of temperature on the mortality and growth of the lobster (Homarus gammarus L.) in its first year

Experiments were carried out with newly hatched lobster larvae at temperatures of 120, 140, 160, 180, 200 and 220C. After about two months the constant temperature of 140C was changed to a fluctuating temperature corresponding to that at a depth of 20m outside the station, which should simulate as closely as possible the lobsters' natural temperature environment in the sea. The initial temperature shock did not seem to cause increased mortality during the first few days. Seen over the whole experiment period, the mortality was greatest at 120C and at the natural temperature. A temperature difference of 20C between the individual batches was sufficient to give a significant time difference from hatching to the fourth stage. The frequency of moulting fell with falling temperature and increasing number of moults. Even at the same temperature there were great individual differences in rates of growth. (JIW)