| A | B |
|---|
| Biomass | The mass of living organisms |
| Swim bladder | Used by some fish to maintain a neutral buoyancy |
| Radiolarians | Build hard shells (tests) out of silica |
| Foraminifers | Produce a hard test made of calcium carbonate |
| Copepods | Includes shrimp, crabs and lobsters |
| Nektonic organisms | Include fish, squid, sea turtles and marine mammals |
| Lungers | Grouper fish are an example |
| Cruisers | Tuna fish are examples |
| Cetacea | Whales, dolfins and porpoises |
| Sirena | Manatees and dugongs |
| Carnivora | Otters, polar bears and walruses |
| Gray whales | Longest migration of any mammal |
