Behavioral mechanisms influencing molt frequency in the American lobster, Homarus americanus Milne Edwards

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The dominance relationship established among communally held juvenile lobsters (Homarus americanus Milne Edwards) results in an increased time between molts of subordinates, slowing their growth. The experiments reported here elucidated some of the mechanisms of this behaviorally mediated change in growth rate. Rearing the lobsters in pairs on either side of a partition allowing chemical or visual communication showed that neither were sufficient to cause the decrease in molt rate. Removal of the claws reduced the extent of the molt delay and altered, but did not prevent, the development of the dominance relationship. The lobsters must be paired before proecdysis begins for the molt delay to occur. Most of the delay can be attributed to a lengthening of the Do phase of proecdysis. Observations on the feeding behavior of pairs separated and together at feeding time showed the subordinates did not feed as readily or as rapidly as dominants. The slower growth rate of the subordinate may be due to a lower food intake. © 1982.

Publication Title

Journal of Experimental Marine Biology and Ecology