They find shells that other crabs have left behind and use them
Answer:
Bacterial genes are organized into clusters of coregulated genes, that are regulated such that they are all turned on or off together.
(hope this helps)
The crayfish have its nerve cord on the ventral side rather than on the dorsal side. The ventral side is under the Crayfishes' exoskeleton, as opposed to the dorsal side where the exoskeleton is . If it is attacked it will be from the dorsal side and the nerve cord would be snapped easier. The function of the nerve cord is that if it gets attacked by a predator they will go for the top and it will still be able to move.
