What Is a Food Chain?
A food chain refers to the series of events occurring in an ecosystem, where a living species, including an animal, bird or an insect eat other organisms, which later becomes prey for another larger organism. The flow of nutrients and energy from one organism to another at different trophic levels forms a food chain.
The food chain also explains the feeding pattern or relationship between living organisms. A trophic level refers to the sequential stages in a food chain, starting with producers at the bottom, followed by primary, secondary and tertiary consumers. Every level in a food chain is known as a trophic level.
Also Refer: Food Web
The food chain is classified into two different types, they include:
- Grazing food chain
- Detritus food chain
What is the Grazing Food Chain?
The food chain in which the energy in the lowest trophic level is derived from photosynthesis is termed as a grazing food chain. In an aquatic ecosystem, this type of food chain is the major conduit for energy flow. The starting point in a grazing food chain are the producers- plants and the first energy transfer is from plants to herbivores. There are mainly two types of grazing food chains and they are as follows:
- Predator chain.
- Parasitic chain.
Examples of Grazing Food Chain
This kind of food chain depends on energy captured by autotrophic plants and the flow of this captured energy to herbivores. The phytoplankton is eaten by zooplankton, the zooplankton is eaten by fishes or grasses, then these grasses are eaten by rabbits, and finally, the rabbit is eaten by a fox.
The small plants or grass is eaten by a deer, and the deer is later eaten by a lion.
Read more: Grazing food chain
What Is the Detritus Food Chain?
The detritus food chain begins with dead organic materials is called a detritus food chain. Dead organic matter and the organisms feeding on the dead and decaying matter are referred to as detritivores or decomposers. These detritivores are eaten by predators. Unlike the grazing food chain, the detritus food chain produces a large amount of energy to the atmosphere.
Detritus food chains are found in a variety of places such as the bottom of the ocean, sea, ponds and also in lakes. Compared to other photosynthetic organisms, they carry out photosynthesis in dark places. Thus, their ecosystems are less dependent on direct solar energy.
Examples of Detritus
The type of food chain that starts with the leaves of a mangrove tree.
When the leaves of a red mangrove tree fall into a shallow water body, only about five per cent of the leaves are eaten by phytophagous insects before they fall.
The parts of the leaves are eaten by smaller organisms like insect larvae, crabs, copepods, etc. Later these organisms are consumed by fishes who are carnivores. Finally, these fishes are eaten by larger fishes or fish-eating birds.
The type of food chain that starts with the dead organic wastes. When these wastes are consumed by microbes like bacteria or fungi. Later, these microscopic organisms are consumed by other detritivore organisms like snails, earthworms and so on.
Read more: Detritus food chains
|Grazing food chain||Detritus food chain|
|In the grazing food chain, producers (autotrophs/green plants) serve as a source of food and constitute the first trophic level.||In detritus food chain begins, detritivores or decomposers feed on the dead and decaying matter and releases the nutrients back into the atmosphere.|
|Source of Energy|
|Energy for the grazing food chain is obtained directly from the sunlight.||Energy for the detritus food chain is obtained from the remains of detritus.|
|A grazing food chain is usually larger compared to the detritus food chain.||Detritus food chain is usually smaller compared to the grazing food chain.|
|This type of food chain adds energy into the ecosystem.||This type of food chain utilizes energy from the detritus, ensuring less wastage with more utilization.|
|Role in the Food chain|
|Grazing food chains fix inorganic nutrients.||Detritus food chain helps in fixing inorganic nutrients.|
|Grazing food chain involves all macroscopic organisms.||Detritus food chain involves subsoil organisms, which can be macroscopic or microscopic.|
Also Refer: Differences between Autotrophs and Heterotrophs
There are many more differences between grazing and detritus food chains. Stay tuned with BYJU’S Biology for more differences and other Biology related topics.