Egg production in the American lobster, Homarus americanus

Egg production in most feral populations of the American lobster is synchronized and predictable. Smaller females spawn on an alternate year cycle, but those larger than 120 mm carapace length spawn more frequently, often three times in five years. Mating usually occurs immediately after the female molts, but males can recognize and copulate with uninseminated females prior to spawning. One copulation can provide sufficient sperm to fertilize two successive broods, which reduces the impact of reduced molting frequency as the females age. Temperature plays a major role in egg production, influencing size at maturity, time of spawning, coordination of the molting and spawning cycles, time of hatch, and egg attachment and incubation success. Higher temperatures have an adverse effect on reproduction; cultured females spawn infrequently and rarely carry their eggs to hatch. However, when they are returned to a temperature cycle that includes low winter and moderate summer water temperature, their egg production approximates that obtained with feral females.