Ecology is the science of the relationships between organisms and their environments.
Paramecium (paramecia-plural) is a single-celled microscopic organisms generally found in fresh water ponds or lakes. Paramecium has some animal-like behavior, never the less they are not classified as an animal, instead they belong to the Protista Kingdom. While, classification is not the primary goal of this article, I think it is important to show how paramecium fit within the Protista Kingdom.
Organisms in the Protista Kingdom are called protists. Protists can be divided into Algae (plant-like protists), and protozoa (animal-like protists), including paramecium.
Being able to move on their own is one animal-like characteristic of paramecia. The mobility of paramecium is accomplished by tiny hair-like structures called cilia that cover the outside surface of the organism. Cilia move like boat oars to push a paramecium through the water. Changes in the movement of the cilia allow the organism to move backwards and even change the angle of direction.
Reproduction in paramecuim is mainly asexual binary fission. The paramecium literally divides in half with each half having the same cell content. Off the two halves go to grow and divide forming more paramecium. The density of population influences how often paramecium divide, increased density decreases the reproduction rate.
Generally, paramecium reproduce sexually in stressful conditions, such as high density population. Sexual reproduction doesn’t produce new daughter cells, instead it seems to be rejuvenating for the pair of paramecium involved. A mating pair come close and attached together from side of oral groove. They join, share genetic materials, then separate with each taking one-half of their partners genetic material. No new paramecium are produced but the pair seem to have new life.
A symbiotic relationship is a close and often long-term interaction between two different species. Some paramecium form a symbiotic relationship with algae. The algae lives inside the paramecium and both organisms benefit. The algae has a safe place to live. One plant-like characteristic of algae is their production of food via photosynthesis. This food can be used by the paramecium.
Paramecium are hunted by Didinium, another unicellular protozoan. Didinium hunt and feed only on Paramecium. Oddly at the microscopic level, the one-celled Didinium hunt down Paramecium and shoot them with what amounts to poison darts with strings attached. When hit by a Didinium dart, the paramecium is paralyzed and reeled in and engulfed by the Didinium. Paramecium are much larger than Didinium. One would think that the Didinium would be stuffed after consuming so much food, but alas it is teens, after a few hours it is on the hunt for another Paramecium.
This is just a brief overview of the ecological niche of a paramecium.
See “Ecology for Every Kid” to find out more about other organisms and how they fit into their ecological niches.