University:
University of Cincinnati
Course:
BIOL 1081 | Biology I
Academic year:

2023
Views:

487

Pages:

2
Author:

blueiecicisykxb

Animal Feeding Mechanisms Description Filter feeders are aquatic animals that use a body structure similar to a filter basket to gather plants and animals suspended in the surrounding water. The filter feeder siphons water into its mouth and then filters it to obtain small organisms to digest. The tube sponge is a filter feeder. Other examples include flamingos, tube worms, clams, barnacles, and baleen whales. Substrate feeders live in or on their food source and eat their way through it. Examples of substrate feeders include caterpillars and earthworms. Caterpillars eat their way through the green tissues of leaves. Earthworms eat their way through the soil, ingesting soil particles containing partially decayed organic material as they go. Fluid feeders obtain food by sucking or licking nutrient-rich fluids from live plants or animals. Fluid feeders have mouth parts that are adapted to pierce or rip skin or leaf tissue. The same or other mouth parts are used to suck or lick the blood or sap that is their food. Examples of fluid feeders include mosquitoes, ticks, aphids, spiders, bees, butterflies, vampire bats, and hummingbirds. Bulk feeders include many animals and most vertebrates (including humans). Bulk feeders ingest fairly large pieces of food and some, like the great blue heron, swallow their food whole. Other bulk feeders use tentacles, pincers, claws, fangs, or jaws and teeth to kill prey, to tear off pieces of meat or vegetation, or to take in mouthfuls of animal or plant food. Example The Four Stages of Processing Food After an animal has obtained its food, the nutrients in the food must get into the individual cells of the animal's body in a usable form. The essential function of an animal's digestive system is to break food down into small, soluble units that can pass through cell membranes. The digestive system breaks down food into useful substances that can be absorbed into the circulatory system. The circulatory system transports these substances to the individual cells of the body. Whatever an animal's source of food, type of food, or feeding method, digestion of food occurs in four stages: 1. Ingestion—the taking in or eating of food 2. Digestion—the breakdown of food by mechanical and chemical processes into molecules small enough for cells of the body to absorb 3. Absorption—the transport of the products of digestion from the digestive system into the circulatory system, which distributes them to the rest of the body 4. Elimination—the removal of undigested solid waste matter from the body Although the function of the digestive system is the same in all animals, the length of the digestive tract varies according to the feeding habits of the species. Herbivores and omnivores (including humans) usually have longer digestive tracts, relative to their body size, than carnivores. For example, compare the digestive tracts of a rabbit (a herbivore) and a fox (a carnivore). Because the cellulose walls in plant tissues are more difficult to digest than animal tissues, most herbivores have relatively longer digestive tracts, which allows the extra time needed for digestion.