What are they?
Lobsters are ten-legged (decapod) crustaceans.
The American lobster is the only species of clawed lobster in the Northwestern Atlantic region.
Where are they?
The American lobster is distributed throughout the Northwest Atlantic from the Straights of Bell Isle, Newfoundland to Cape Hatteras, North Carolina.
They are most abundant in coastal zones at depths of less than 150 ft. (~50 m). The greatest abundance of lobster occurs within the Gulf of Maine — from mid-coast Maine to Southwest Nova Scotia.
Growth
American lobster is a longed-lived species known to reach more than 40 lbs. (18 kg).
Age is unknown because all hard parts are shed and replaced at molting (shedding), leaving no accreting material for age determination. In Massachusetts, shedding typically occurs between June and October.
Lobsters at minimum legal size are generally considered to be between 5 and 7 years of age based on hatchery observations. Maximum age is generally considered to be between 30 and 40 years.
Biology
Fertilized eggs are carried on the female abdomen for a 9 to 12 month period of development prior to hatching.
Female lobsters carry between 1000 and >100,000 eggs depending on the size of the female.
Hatching typically occurs over a 4 month period from May through September. In Massachusetts we typically see peak hatching from late-June through early-July.
Egg-bearing Females
It is unlawful for any fisherman to take or possess any egg-bearing female lobster or female lobster with the egg mass removed, at any time.

Regulations in red are new this year.
Purple text indicates an important note.