Locomotor activity and food consumption by the lobster Homarus gammarus

Abstract

Locomotor activity and food consumption by male, unberried and berried female lobsters were recorded for five‐day periods during 16 months. Annual average locomotor activity was similar in all three categories, but food consumption was in the ratio of 3 (males): 2 (unberried females): 1 (berried females). Since lobsters are caught in baited traps, this result suggests that, in a commercially exploited population with a 1:1 sex ratio, fishing mortality is likely to be in the ratio of 2 males:1 (females).

The time when a female lobster hatches her eggs and the time of her peak of locomotor activity were simultaneously recorded; both were found to occur after sunset and at about the same time. The proportion of locomotor activity occurring at night was found to vary. All categories of lobsters were most nocturnally active around the spring equinox and least so around the summer solstice.