An amazing world exists just beyond the naked eye. Pond water is one place to investigate this landscape of single cells that behave as independent organisms. Biologists have named this group, the protists. This report will fill you in on ones that can be most likely found in ponds.
Protist, were around long before plants and animals appeared. Fossil protists have been found in rocks dated at more than 1.8 billion years old. In fact, your local pond is a very good place to find protists very similar to those that started the lines of multi-cellular life --and these organisms seem relatively unchanged from that ancient time.
The simplest of all animals is the protazoa in Greek this name means "first animal." There are four major classes of the protazoa. The simplest of these are the amoeboid. The amoeboid are found under the class name Sarcodina, some examples of these organisms are amoeba proteus, endamoeba coli, and endomoeba histolytica. These organisms are mainly parasites and are mostly free living. They reproduce by binary fission where they split themselves in half.
Another more complex class is called the Infusoria. Some examples of the Infusoria are the Paramecium caudatum, Stentor, and Balantidium Coli. These organisms move by cilia which are tiny cells that give the cell momentum to move which looks like swimming. These organisms can reproduce asexually by binary fission or sexually. Some are parasitic to man and lower animals.
A third class of protazoa is the Mastigophora, the Euglena viridis, Volvox globator, Trichonympha campanula, and Trichomonas honnis are just some of the many species that are found in this class. In this class some have chlorophyll, which allows them to produce their own food others, are pathogenic to man. These organisms use long thread like appendages called flagella to move.
The fourth and final class of protazoa is the Sporazoa. The Monocystis, Nosema bombycis and Prospora gigantea belong to this class of protazoa.
