amoebamoeba (genus)

There are many species in this genus. They are very difficult to tell apart.



Nikon Microscopy U

Amoebas, like all protists, are single-celled organisms. Cells are the building blocks for all life forms. "Single-celled" means that amoebas have only one cell for their entire body. A human body has more cells than you can count. The inside of an amoeba is a jelly-like fluid called cytoplasm. Bits of food and other materials float around in the protoplasm. Amoebas are so tiny that you need a microscope to see them. They live in water, including lakes, ponds, streams, rivers, and puddles. Some can even live in the bodies of animals.

The most important part of an amoeba might be the pseudopod (pronounce it "sudopod"). The psuedopod is used to help the amoeba move, and also to eat. It is a part of the amoeba's body that it can stretch out and pull itself with. Or, to eat, the amoeba stretches out the pseudopod, surrounds a piece of food, and pulls it into the rest of the amoeba's body. Amoebas reproduce (make more amoebas) by a process called binary fission. This means that one amoeba can split in half and make two identical new amoebas.

Amoebas eat algae, bacteria, other protozoans, and tiny particles of dead plant or animal matter. They spend most of their time attached to the bottom or to plants. Sometimes they float freely in the water. They do this as a "swarm." All the amoebas of the same species will unattach from the bottom or plants and float around until they land in a new place and re-attach. Animals that eat amoeba include plankton feeders, such as mussels and water fleas.