The first pair of legs is very different than the other leg pairs, Lobsters have two very large claws both with a different purpose. One is used to crush its prey while the other is used to hold and cut its prey. The crusher claw is bigger with large "teeth" to enable it to crush its prey. While, the cutter claw is much smaller and has many little "teeth" that enable the lobster to tear or cut fish prey.
The Lobsters' have three pairs of antennas; two short pairs and one long pair. The long antenna allow the lobster to feel its way around the rocky bottom. While the short pairs of antenna are used to sense chemicals in the water.
In this picture you can clearly see the large antenna and the two completly different claws.
Lobsters like to live in rocky bottoms covered with algae. The algea attracts it's prey like: Sea Urchins, Mussels, Flounder, Sand Shrimp, and Rock Crab. When lobsters are small, they are prey for several fish such as cod, tench, flounder, sculpin, wolffish, ocean pout, monkfish, and dogfish. On the other hand, when they are adults, lobsters are much less vulnerable. The only large predator for adult lobster is man. The American lobster can be found in the Atlantic only along the North American coast. They are very abundant in the gulf of Maine and of the coast of Nova Scotia.