| A | B |
|---|
| plankton | small living things in water that are food for many fish |
| mussel | a water animal that looks similar to a clam |
| hatchling | a newly-hatched animal |
| ecosystems | interaction of organisms in their environments |
| underside | the bottom side of something |
| ridges | raised narrow strips |
| protection | synonym for safety |
| muscles | body tissues that move body parts |
| flippers | broad, flat body parts used for swimming |
| current | a flow |
| coral | a substance made up of the skeletons of tiny sea animals |
| awkward | uncomfortable or uncoordinated |
