Planktons in the Ocean
Planktons are really small organisms that live in water and water surface. Planktons are varies in size, but most of them are really small, therefore, they can’t swim against water current and they follow water currents to move around. Planktons are the foundation of ocean food web and they are the food for many animals, including small fish and mainly whales. These organisms include animals, protists, algae or bacteria. The name plankton is derived from the Greek word “planktos” which means wanderer. Planktons can be classified as 2 main categories, phytoplankton and zooplankton. Those 2 categories will be explained below:
Phytoplankton
Phytoplanktons are planktons that use photosynthesis to create their own energy. They float near water surface, and mostly come in round shape and single celled. Phytoplankton can be divided into 2 categories, diatoms and dinoflagellates.
· Diatoms are single celled algae and they often live together and forming a chain.
· Diatoms are single celled algae and they often live together and forming a chain.
· Dinoflagellates are small microorganisms that have 2 tails or flagella. They come in different kind of shapes and sizes. Some of them use photosynthesis for making their own energy, and some of them wrap themselves around their food and absorb it. Some of them can make their own light using bioluminescence.
· The algae are also classified as phytoplankton, and they also provide food for other ocean organisms. Some example of algae are phaeophyta and cyanophyta (blue-green algae). They change nitrogen in the ocean into nitrates, which can be eaten by ocean plants.
Zooplankton
Zooplanktons are ocean animals that cannot swim, or are weak swimmers, but mostly they move by following the ocean current. These planktons can be found in the shallow area of the ocean, or in the deer area of the ocean. These planktons are also varies in size, from just tiny single celled organisms until giant planktons such as jellyfish. There are 2 types of zooplankton, holoplankton or permanent plankton, and meroplankton which are fish larvae that will soon developed into larger organisms. There are some examples of zooplankton that are going to be explained in the session below:
· Foraminifera are microscopic single celled planktons which have hair-like hands called pseudopodia that can be used to catch food. When foraminifera died, their bodies will be drown into the bottom of the ocean, and almost 30% of the ocean floor is made up of these organisms, even limestone and chalk came from their dead shells!
· Foraminifera are microscopic single celled planktons which have hair-like hands called pseudopodia that can be used to catch food. When foraminifera died, their bodies will be drown into the bottom of the ocean, and almost 30% of the ocean floor is made up of these organisms, even limestone and chalk came from their dead shells!
· Radiolarians are round-shaped organisms. They also have pseudopodia to catch food. Their bodies will also sink to the ocean floor when they died, and they can even form sedimentary rocks.
· Ciliates are planktons that have cilia (hair-like extensions) all around their body to move around and to catch food as their hands.
· Jellyfish are also considered as plankton. They are weak swimmers and rely on water currents to move. Mostly, they can only move up and down. They have stingy tentacles that they use to paralyze their prey.
· Siphonophores are sometimes mistaken as jellyfish, but actually they are not. They are composed of many different animals which have their own roles, such as being the mouth, tentacles, and so on.
· Krills are whales’ favorite food! They can be found in sunlight and twilight zone, and some of them even have their own light (bioluminescent).
written: Wafina Mario
written: Wafina Mario