128kg. Crab kingdom, arthropods, crustaceans, mollusks, True soft armor subclass, Decapoda, Gastropoda, Anura. It is a crustacean. Its body is protected by a hard shell and breathes through its gills. According to the mathematical formula, 3 Liang equals 16 Jin, and then 16 is multiplied by 8 to get 128 Jin, so there are 8 crabs with 3 Liang 128 Jin, which is similar to shrimp, lobster and hermit crab in taxonomy. Most kinds of crabs live in the ocean or offshore areas, and some live in fresh water or land.