Heterotrophic Nutrition

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In through siphon

Mucus on gills traps particles

Cilia transport particles/water current (along food groove) towards mouth

Enzymes in intestine breakdown food

Carbohydrates absorbed as monomers

The Antarctic krill manages to directly utilize the minute phytoplankton cells

Feeding Mechanism

Slide 44

How a filter feeder creates a feeding current:

Cilia

Beating/ moving rhythically

Feeding Mechanism

Slide 45

Extra-cellular digestion:

Body consists of thin threads (hyphae)

Hyphae secrete enzymes that diffuse through wall onto food

Enzymes hydrolyse materials in food to monomers

Monomers then absorbed into hyphae by F.D. and A.T.

In fungi (e.g. saprophytic fungi), cilia not involved in moving food

Feeding Mechanism

Slide 46

Feeding with Tentacles

When feeding, these animals project tentacled structures out of the tube to catch food particles in the flowing water. By using cilia on their tentacles, these worms select particles based on size.

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Detritus feeding

detritus, consists of bacteria and the remains of finely chopped up algae and decaying fragments of animals, as well as countless numbers of stranded microscopic, one-celled green plants which are called diatoms.

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Biting & Chewing Mouthpart

Biting and chewing food is a multisensory task that requires a high level of coordination of all parts of the mouth.

Slide 49

chewing mouthparts have toothed jaws that bite and tear the food (beetles, cockroaches, ants, caterpillars, and grasshoppers).

piercing-sucking mouthparts are usually long slender tubes that are forced into plant or animal tissue to suck out fluids or blood. (mosquitoes, aphids).

sponging mouthparts are tongue-like structures that have spongy tips to suck up liquids or food that can be made liquid by the insect's vomit (house flies, blow flies).

siphoning mouthparts are long tubes used for sucking nectar (butterflies, moths).

Biting & Chewing Mouthpart

Slide 50

Fluid feeding

An external type of digestion is sucking or fluid feeding. A wide variety of animals and insects are adapted to take in liquid food, either from plants or animal juices. All spiders use sucking as their digestive means. They inject digestive enzymes into the prey and allow the exoskeleton to contain the juice as internal body parts are liquified.