Summary:
- Marine organisms range in size from tiny bacteria to the largest known animal, the blue whale.
- All are adapted for life in salt water.
- Most plankton are too small to see with the unaided eye.
- Most nekton are fish, although some are mammals.
- Benthos bury in the sediment, attach to rocks, or crawl over the seafloor.
- Some benthos live near vents on the deep ocean floor, where hot water pours out of the vents.