radiant energy of the Sun in the presence of chlorophyll? All green plants and certain bacteria which can produce food by photosynthesis come under this category and are called the producers. Organisms depend on the producers either directly or indirectly for their sustenance? These organisms which consume the food produced, either directly from producers or indirectly by feeding on other consumers are the consumers.
Consumers can be classed variously as herbivores, carnivores, omnivores and parasites. Can you give examples for each of these categories of consumers? Imagine the situation where you do not clean the aquarium and some fish and plants have died. Have you ever thought what happens when an organism dies?
The microorganisms, comprising bacteria and fungi, break-down the dead remains and waste products of organisms. These microorganisms are the decomposers as they break-down the complex organic substances into simple inorganic substances that go into the soil and are used up once more by the plants. What will happen to the garbage, and dead animals and plants in their absence? Will the natural replenishment of the soil take place, even if decomposers are not there?
While creating an aquarium did you take care not to put an aquatic animal which would eat others? What would have happened otherwise? Make groups and discuss how each of the above groups of organisms are dependent on each other. Write the aquatic organisms in order of who eats whom and form a chain of at least three steps.
Would you consider any one group of organisms to be of primary importance? Why or why not? Trophic levels