sentence: Shells are many different shapes, sizes, and colours.
sentences_before: Snails are invertebrates, which are animals with no backbones. The shell on the snail helps protect it, and also reduces the loss of water by evaporation.
sentences_after: Snails do not breathe through their mouths, instead they have a breathing hole under their shells.
concept_name: shell
headings: Snail Body parts Shell
categories: Gastropods