Crab is a very common animal that lives in the water.Specifically, crabs belong to the arthropod phylum Malacostraca Decapoda, which is an arthropod and a crustacean in arthropods, but not a mammal.The difference between mammals and crustaceans is very large, because mammals belong to Chordata, while crustaceans belong to Arthropoda, so crabs can not be considered mammals.

In fact, as a crustacean, crabs are very different from mammals.From the point of view of reproductive methods, crabs use oviparous reproductive methods, and each reproduction can lay many eggs, even up to millions of eggs; However, the reproductive mode of mammals is viviparity, which is a very typical feature.From the appearance characteristics, crabs have a hard shell on the outside of their bodies, but mammals have a layer of fur on the outside of their bodies, which is quite different.From the way of breathing, crabs breathe with gills, but mammals have lungs, a more advanced structure, and breathe with lungs.According to the above differences, crabs can not belong to mammals.

2. where do crabs live

Judging from the living environment of crabs, crabs live in water and are regarded as aquatic animals.Many life activities of crabs are completed in the water.For example, they hunt in the water, and their food is fish, shrimp and mollusks in the water.For example, their reproductive activities are also carried out in the water.It can be seen that the environment in the water is very important for crabs.