The first few years of the life of Homarus americanus are perilous. From every 50,000 eggs, only about two lobsters survive to legal harvesting size.
After carrying her eggs (as many as 100,000 of them) for 9 to 12 months, the female lobster sheds them indiscriminately. Many are eaten before they hatch. The ones that hatch live in a larval stage, the size of a mosquito, undergoing three molts over a period of 15 days to a month. During this time, they float in the top few inches of the ocean and many are consumed by plankton-eaters. After the third molt, larvae seek a place to hide as they become miniature versions of an adult lobster — a precarious time as they travel up and down in the water column. After they have settled on the ocean floor, tiny lobsters eat what drifts into their hiding place, but as they grow, they must forage for food, during which time they must seem to other sea creatures as delicious hors d’oeuvres.
A lobster will molt as many as 25 times in the first five to seven years of its life, at which time it will weigh about a pound. After that, a lobster will molt only once every year or two. The lobster grows a new shell under the old one, which splits, allowing the lobster to wriggle out. The new shell is soft, and newly molted lobsters are especially vulnerable to predation. Females mate just after molting. Males can mate just before or just after molting.
Source: The Lobster Institute (University of Maine) and The American Lobster (Pictou-Anmtigonish Regional Library, Nova Scotia).