What Divers Should Know About Lobster

Lobsters inhabit a wide range of marine environments across all oceans, found on rocky, sandy, or muddy bottoms from the shoreline to beyond the edge of the continental shelf. Typically, these malacostracan decapod crustaceans reside in crevices or burrows on the seafloor. While smaller, younger individuals often remain in shallow, sheltered spots under rocks, larger, older lobsters are commonly encountered in deeper seas, undertaking seasonal migrations back to shallower waters. These creatures possess long bodies with muscular tails, and notably, three of their five pairs of legs feature claws, with the first pair being significantly larger.

Moving slowly across the seabed by walking, lobsters measure generally between 25–50 cm (10–20 in) in length. Despite their deliberate pace, they exhibit a remarkable "caridoid escape reaction," propelling themselves backward at speeds up to 5 m/s (11 mph) by curling and uncurling their abdomens when threatened. As omnivores, their diet primarily consists of live prey such as fish, mollusks, other crustaceans, and worms, along with some plant life. They will scavenge when necessary, and while historically thought rare in the wild, instances of cannibalism have been observed due to specific population dynamics. A unique ecological trait involves the genus Symbion, tiny symbiotic animals found exclusively on their gills and mouthparts.