American Lobster

The American lobster, Homarus americanus, is one species of lobster found on the Atlantic coast of North America. Within North America, it is also known as the northern lobster, Atlantic lobster or Maine lobster. It thrives in cold, shallow waters where there are many rocks and other places to hide from predators and is both solitary and nocturnal. It feeds on fish, small crustaceans, and mollusks.

The American lobster is found as far south as North Carolina, but is famously associated with the colder waters around the Canadian Maritimes, Newfoundland and Labrador, Maine, Massachusetts, Rhode Island and New Hampshire. 1 They commonly range from 8 to 24 in 20 to 61 cm in length and 1 to 9 lb 0.5 to 4.1 kg in weight, but have been known to reach lengths of well over 1 160 yd 1 m and weigh as much as 44 160 lb 20 kg or more, making this the heaviest marine crustacean in the world. 2 An average adult is about 9 160 in 230 mm long and weighs 1.5 to 2 lb 680 to 910 g .

The adult American lobster's main natural predator is the codfish, but other enemies include haddock, certain species of seals, flounder, and other lobsters. Overfishing of cod in the early 20th century has allowed the lobster population to grow enormously.

American lobsters molt two to three times per year while juvenile, but only once a year or less when fully mature which is about four to seven years old . When a lobster nears its next shedding period, it starts to grow a new shell underneath the current one, and the outer shell becomes very hard and darkens. The line that runs along the back of the lobster's carapace begins to split, and the two halves of the shell fall away. Claws and tail pull out from the old outer shell, as the inner shell is very malleable. The old shell is often eaten for calcium recovery and the leftovers are sometimes buried.

Females usually mate right after molting, but mating in between molts, known as intermolt mating, can occur. Larger females can store sperm for several batches of eggs from a single coupling. All females store the sperm to fertilize eggs later, not at the time of copulation. While getting ready to molt the female finds the den of a suitable male and visits it several times. When finally ready to molt, the female does so in that den. After the molt the male waits for the shell to start to harden, gently stroking the paper thin new shell with his large antennae. After several minutes the male rises on his claws and tail, and uses his legs to flip the female over and get on top. The male has a pair of hardened swimmerets, or fins on the bottom, that match a pair of swimmerets on the female that have an opening between them. The sperm, contained in a gelatinous blob called a spermatophore slides down notches in the male's swimmerets into the female. The outside end of the spermatophore hardens to block the hole. The receptacle on the female is part of her shell so she must use the sperm before her next molt or lose it. The male dismounts, and then may eat the female's shell. The female stays in the den for several days while her shell hardens more. Lobsters do not mate for life, contrary to some myths. The female seeks the most alpha male she can find, and the male mates with as many females as he can.

In the first two weeks after molting, lobsters are very vulnerable, as their shells are so soft they can neither move very fast nor defend themselves with their claws. At this point, they are often referred to as "shedders" in the industry. They often fall prey to other lobsters, especially egg-bearing females, who become defensive when carrying eggs.