The speed of maturation at this stage may be accelerated by warmer water temperatures. Usually the eggs hatch in the summer, and the newly released larvae float to the surface where they feed upon smaller planktonic organisms and-undergo three moults, each time growing larger, and more similar to an adult. In three to six weeks, depending on the temperature, the juvenile lobster descends to the sea bottom. At this stage its total length is about 15 mm. The mortality rate of larvae is very high, and only about one per cent of the floating larvae may settle on the ocean floor.
Growth slows down progressively as the juvenile lobster grows to adulthood.
Since lobsters grow faster in more temperate waters they may moult more often. In the Northumberland Strait, for example, where summer water temperatures may reach 20 C, a lobster at the current canner minimum of 63.5 mm carapace length, can moult twice in one year. Once a lobster has replenished the flesh within its new shell, it will be about 50 per cent heavier than before a moult. So in one year a lobster from the Northumberland Strait would grow from 200 g to 450 g, and would moult twice, whereas his counterpart in a cooler habitat would average 300 g, and moult only once. Temperature is also a factor in the age at which a lobster attains sexual maturity.