Fill in the Blanks VERTEBRATE ANIMALS. 1 pg 50Online version This activity is created for students to play and learn. Its level is Primary School, 3rd grade. by Gonzalo Barral 1 Mammals scales egg fur feathers head tail limbs skin hair gills lungs The bodies of vertebrates have a , a trunk and . Many vertebrates also have a . Fish and reptiles have all over their bodies . Amphibians have bare . Birds have and mammals have or . Birds breathe using their . Fish breathe using their . grow inside the mother's womb . Fish grow inside an .