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
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.
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.
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).
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.
