Protozoan & Vorticella Organisism
Protozoan & Vorticella Organisism
Protozoa, collective name for animal-like, single-celled organisms, some of which may form colonies. In the classification followed in this essay the protozoa are placed in the kingdom Protista with other single-celled organisms that have membrane-enclosed nuclei. Protozoa have little or no differentiation into tissue systems. Several phyla are commonly recognized.
They include flagellated Zoomastigina, many species of which live as parasites in plants and animals; the amoeboid Sarcodina, which includes the Foraminifera, and Radiolaria both important components of the plankton; ciliated Ciliophora, many with specialized structures suggesting the mouth and anus of higher organisms; Cnidosporidia, parasites of invertebrates, fish, and a few reptiles and amphibians; and Sporozoa, many species of which are parasites of animals (including humans). More than 20,000 species are known, including such familiar forms as paramecium and amoeba.
Most species are found in such aquatic habitats as oceans, lakes, rivers, and ponds. They vary in length from 2 to 70 micrometers. Protozoa obtain their food by ingesting bacteria, wastes products of other organisms, algae, or other protozoa. Most species are motile, either by whiplike structures called flagella, hairlike structures called cilia, or amoeboid motion, a streaming type of movement involving the formation of pseudopods (footlike extensions).
VORTICELLA
Vorticella; are single celled heterotrophic protists. Known as ciliates (from the phylum Ciliophora), Vorticella remain anchored in placed using a large stalk (located in the aboral end), while using their cilia to collect food into the gullet. The gullet can be described as a cell, taking food in at the oral end.
Ciliates are characterized by conjugation. Nuclei are exchanged between tubes connecting different Vorticella cells as a means of reproduction.