Feeding Mechanisms of Animals

 

By: Dr. Akalesh Kumar Verma, Assistant Professor, Cotton University, Guwahati, Assam.

Feeding Mechanisms of Animals

The act or process of eating or being fed is known as feeding. There are five major types of feeding mechanism shown by different groups of animals.

1.      Suspension Feeders and Filter Feeders

2.      Fluid Feeder

3.      Substrate Feeders

4.      Bulk Feeders

5.      Deposit Feeder

1.      Suspension Feeders and Filter Feeders

Many aquatic animals are suspension feeders, which eat small organisms or food particles suspended in the water. For example, clams and oysters feed on tiny morsels of food in the water that passes over their gills; cilia sweep the food particles to the animal's mouth in a film of mucus. Filter feeders such as the humpback whale move water through a filtering structure to obtain food. Attached to the whale's upper jaw are comblike plates called baleen, which strain small invertebrates and fish from enormous volumes of water.

2.      Fluid Feeder

Fluid feeders suck nutrients rich fluid from a living host. Mosquito pierced the skin of human host with hollow, needlelike mouthparts and is consuming a blood meal. Similarly, aphids are fluid feeders that tap the phloem sap of plants. In contrast to such parasites, some fluid feeders actually benefit their hosts. For example, hummingbirds and bees move pollen between flowers as they fluid-feed on nectar.

3.      Substrate Feeders

Substrate feeders are animals that live in or on their food source. This leaf miner caterpillar, the larva of a moth is eating through the soft tissue of an oak leaf, leaving a dark trail of feces in its wake. Termites are substrate feeders that destroy wooden structures by burrowing through the wood, feeding on the cellulose. Some other substrate feeders include maggots (fly larvae), which burrow into animal carcasses (dead body of an animal).

4.      Bulk Feeders

Most animals, including humans, are bulk feeders, which eat relatively large pieces of food. Their adaptations include tentacles, pincers, claws, poisonous fangs, jaws, and teeth that kill their prey or tear off pieces of meat or vegetation. In this amazing scene, a rock python is beginning to ingest a gazelle it has captured and killed. Snakes cannot chew their food into pieces and must swallow it whole even if the prey is much bigger than the diameter of the snake. They can do so because the lower jaw is loosely hinged to the skull by an elastic ligament that permits the mouth and throat to open very wide. After swallowing its prey, which may take more than an hour, the python will spend two weeks or more digesting its meal.

5.      Deposit Feeder

An earthworm is a deposit feeder, a special type of feeder that ingests partially decayed organic material along with its substrate. As an earthworm eats its way through soil, it excretes the inorganic material and digests the organic matter the soil contains. The material excreted by the worm as it burrows and eats its way through the soil is called the worm cast.