A marine crab before its shell has hardened after molting, especially the edible species (Callinectes sapidus) of eastern North America in this stage.

• 软壳蟹：一种在蜕皮之后壳还未硬化的海生蟹，尤其是北美洲东部处于这个阶段可食用的种类（软壳蟹）