The muscular system of the lobster brings about movements and constitutes the motor (movement) component of all behavior. It is also the part of the lobster that we eat, particularly as the muscle, or meat, is relatively fat-free. However, it is important for another reason and that is that the lobster, over its lifespan of 50 years or more, shows few signs of aging or of muscular disease. They have two basic muscle fiber types which are grouped in bundles: fast and slow and the muscles are composed of single-type bundles (fast or slow) or mixed bundles. In clawed lobsters, the muscles of the prominent claws change from mixed bundles to primarily slow bundles in the crusher (largest) claw and fast bundles in the cutter or smallest claw. Neuron specialized for muscle (called motor neurons) penetrate into the muscles and are either excitatory (make contractions) or inhibitory (stop contraction). This entire neuro-musculatory (brain muscular) system undergoes remodeling over the entire lifespan of the lobster and particularly at periods of growth, where the animal sheds its old shell and puts on a new, larger shell.
The diagram of the lobster as well as the color picture is from google.com/images
The diagram of the lobster as well as the color picture is from google.com/images