Types of Nutrition in Animals

Nutrition in Animals:

Animals are generally heterotrophic and perform holozoic nutrition. Holozoic nutrition involves the ingestion of complex organic substances. The food of most animals contains large organic substances. In this mode, small or large particles of food are consumed through an opening called the mouth. Then there are hydrolyzed into simpler and soluble forms (digestion). Simplified products are absorbed into the body and the undigested product is removed from the body.

Holozoic nutrition is broadly classified into the following categories –

1. Parasitic Nutrition: It is a mode of heterotrophic nutrition where an organism is known as a parasite. It lives on the body surface or inside the body of another type of organism known as a host. The parasite obtains nutrition directly from the body of the host. Since these parasites derive their nourishment from their host, this interaction is often described as harmful to the host.

Example: Tapeworms, fleas and barancles.

2. Symbiotic Nutrition: Symbiotic nutrition is close and often long-term interaction between two or more different biological species. A symbiotic relationship is where two organisms depend on each other and are both benefited from their relationship.

Example: A certain kind of bacteria lives in the intestines of humans and many other animals. Human can’t digest all of the food that it eats. The bacteria eat the food that the human can’t digest and partially digest it. It allows the human to finish the job. The bacteria benefit by getting food and shelter and the human benefits by being able to digest the food it eats.

3. Saprozoic Nutrition: Nutrition of an animal by absorption of dissolved salts and simple organic nutrients from the surrounding medium. It also refers to feeding on decaying organic matter. In this kind of nutrition, the process is started from half or fully broken down macromolecules. It is a kind of extracellular digestion that is most often carried out through active transportation.

Example: Spiders, house files etc.

4. Coprophagy: Coprophagy is the consumption of feces. It refers to any kind of feces eating including eating feces of other species, other individuals, or its own. These feces contain substantial amounts of semi-digested food.

The most notable feces-eating insect is the dung beetle and the most common is the fly. Pigs eat the feces of humans that leave a significant amount of semi-digested matter.

5. Sanguinivory: Sanguinivory or hematophagy is the habit of certain animals feeding on blood. It feeds on the blood of the vertebrates.

Example: Female mosquito, leeches, vampires, bats, etc.