I believe "life" is more than just the perceived physical substance which we call the body. The body by itself is like covering which needs something ( the soul/energy) to animate it so it can function.
So after the physical death, the person u truly are with all your personality, memories, etc. still lives on in the form of soul/spirit which is/was the energy that animated your physical body.
Believe it or not, lobster and crabs are crustaceans and are a part of the arthropod family, which include caterpillars, cockroaches, and spiders!