Lobsters are large marine crustaceans that belong to the family Nephropidae. They have long bodies and are characterized by their large first pair of claws and muscular tails. They can be found in all oceans, usually on rocky or muddy bottoms, living in crevices and burrows and feeding on plants, mollusks and fish.
All lobster species have their bodies protected by a hard exoskeleton. In order to grow, they must molt their carapace which makes them vulnerable to predators, and some have adapted to changing color until developing a new exoskeleton. These animals have 5 pairs of legs, with the first 3 having claws. The first pair of claws is the largest, which is used for catching prey or for defending or scooping up the sea floor. Due to the specific techniques and diets, lobsters may have specialized claws which may alter their general bilateral symmetry.
The body of a lobster is composed of a cephalothorax – which is actually the head and the thorax fused together, protected by a hard external carapace – and a strong and muscular abdomen which is used for swimming. The head of a lobster has appendages such as antennae, with which it senses movement and food on the sea floor, since they usually live in a murky environment where the eyes don’t play a significant role. On the head there are also present the mandibles, two pair of maxillae and the maxilllipeds.
Large lobster specimens have been estimated to be 60 years of age, although an accurate determination of their age is difficult. There is research that may suggest that the age of the lobster does not influence fertility, as it will not slow down or decrease in quality over time. It has been discovered that older lobsters are actually more fertile than younger specimens. In most vertebrates, telomerase, an enzyme responsible for repairing telomeres (the repetitive ends of chromosomes), is active only during early stages of development.
The aging process is strongly related to the lack of telomerase activity, but it seems that in the case of lobster species, this enzyme continues its activity though the entire adulthood, and it is expressed throughout all the tissues of the body. This telomerase activity has been correlated to the particularly long life span and fertility of lobster species.
Because lobsters grow throughout their entire life time, they are able to reach impressive sizes, with the largest specimen, captured in Nova Scotia, Canada, weighing 20.15 kilograms.