No, crabs are "invertebrate" animals, they do not have a backbone.
no.
gills
They have gills under their mouths that allow them to breathe. When the gills start to dry out, foam forms at the mouth, telling you that the crab has trouble breathing.
Gills.............
The fishes have gills for breathing
Breathing is breathing is breathing whatever you use to do it with. There is no special term or word to my knowledge that specifically means "Breathing with gills".
Crab
They use lungs and gills.
gills are structures in fish for breathing in water while gills chambers are the cavities in which gills are enclosed
Gills
their gills
Gills
breathing tube