In the ocean we have some of the smallest organisms like bacteria, and the now largest living animals, the whales. The ocean is full of life. When looking at a water sample under a microscope the sample will have a great deal of microorganisms moving around. All of these small organisms are referred to as plankton. What is plankton? Plankton is an organism that can’t swim against the current, they can move up and down the water column, but not sideways. All the small algae and animals that drift in the currents are plankton. What´s fascinating is that jellyfish are also plankton, both the ones that float on the surface like the blue bottles and the ones deeper down like the Moon jellyfish. What’s more fascinating is that the largest bone fish in the world the Sun fish or Mola mola is a plankton. Most scientists don’t want to call it a fish but plankton. This is due to the fact (as the picture show) that the Mola don’t have a back fin, they have a long dorsal fin and anal fin. These two fins help them manoeuvre in the water but are not strong enough to swim against the current. The statement that plankton can’t swim against the current applies to the Mola. They move vertically in the water column in hunt of jelly fish. The Molas can grow up to 3000kg and when reproducing they lay over 3 million eggs. This world record holder in amount of eggs and body size for a bone fish is also the largest plankton of the ocean. When they come up to the surface to have birds pick off the parasites that attach to them they can be mistaken for sharks when the dorsal fin sticks out.