What animal cannot undergo senescence and be cut in half?

The animal that cannot undergo senescence and can be effectively cut in half without dying is the Turritopsis dohrnii, commonly known as the "immortal jellyfish." This species has the unique ability to revert to its juvenile form after reaching maturity, allowing it to avoid the aging process. When cut in half, the jellyfish can regenerate and continue its life cycle. This fascinating biological capability makes it a subject of interest in studies on aging and regeneration.