Sponges are mainly sessile Sponges are mainly sessile organisms.organisms.

Because most adult sponges Because most adult sponges can’t travel in search of food, can’t travel in search of food, they get their food by a process they get their food by a process called filter feeding.called filter feeding.

Sponges are pore-bearersSponges are pore-bearersWater outWater out

CentralCentralcavitycavity

WaterWaterinin

• Cnidarians are predators that capture or poison their prey using nematocysts.

Digestion in cnidariansDigestion in cnidarians

• A nematocyst (nih MA tuh sihst) is a capsule that contains a coiled, threadlike tube.

• The tube may be sticky or barbed, and it may contain toxic substances.

• Nematocysts are located in stinging cells that are on tentacles.

• Once captured by nematocysts, prey is brought to the mouth by contraction of the tentacles.

Digestion in cnidariansDigestion in cnidarians

Polyp

Medusa

Mouth

Gastrovascular cavity

Mouth

Digestion in cnidariansDigestion in cnidarians

• The inner cell layer of cnidarians surrounds a space called a gastrovascular (gas troh VAS kyuh lur) cavity.

• Cells adapted for digestion line the gastrovascular cavity and release enzymes over captured prey. Any undigested materials are ejected back out through the mouth.

Hydra eating daphnia

Infection by Infection by AscarisAscaris (ASS kuh ris) is the (ASS kuh ris) is the most common roundworm infection in most common roundworm infection in humans.humans.

Roundworm parasites of Roundworm parasites of humanshumans

Children become infected more often Children become infected more often than adults do.than adults do.

Eggs of Eggs of AscarisAscaris are found in soil and enter a are found in soil and enter a human’s body through the mouth.human’s body through the mouth.

The eggs hatch in the intestines, move The eggs hatch in the intestines, move into the bloodstream, and eventually to into the bloodstream, and eventually to the lungs, where they are coughed up, the lungs, where they are coughed up, swallowed, and begin the cycle again.swallowed, and begin the cycle again.

Roundworm parasites of Roundworm parasites of humanshumans

Pinworms are the most common human Pinworms are the most common human roundworm parasites in the United States.roundworm parasites in the United States.

Roundworm parasites of Roundworm parasites of humanshumans

Pinworms are highly contagious because eggs Pinworms are highly contagious because eggs can survive for up to two weeks on surfaces.can survive for up to two weeks on surfaces.

Its life cycle begins when live eggs are ingested. Its life cycle begins when live eggs are ingested. They mature in the host’s intestinal tract.They mature in the host’s intestinal tract.

Roundworm parasites of Roundworm parasites of humanshumans

Female pinworms exit the host’s anus—Female pinworms exit the host’s anus—usually as the host cell sleeps—and lay eggs usually as the host cell sleeps—and lay eggs on nearby skin.on nearby skin.

These eggs fall onto bedding or These eggs fall onto bedding or other surfaces.other surfaces.

TrichinellaTrichinella causes a disease called causes a disease called trichinosis trichinosis (tri keh NOH sis).(tri keh NOH sis).

Roundworm parasites of Roundworm parasites of humanshumans

This roundworm can be This roundworm can be ingested in raw or ingested in raw or undercooked pork, pork undercooked pork, pork products, or wild game.products, or wild game.

TrichinellaTrichinella

Hookworm infections are common in Hookworm infections are common in humans in warm climates where they humans in warm climates where they walk on contaminated soil in bare feet.walk on contaminated soil in bare feet.

Roundworm parasites of Roundworm parasites of humanshumans

Hookworms cause Hookworms cause people to feel weak and people to feel weak and tired due to blood loss.tired due to blood loss.

Nematodes can infect and kill pine Nematodes can infect and kill pine trees, cereal crops, and food plants trees, cereal crops, and food plants such as potatoes.such as potatoes.

Roundworm parasites of other Roundworm parasites of other organismsorganisms

They are particularly attracted to plant They are particularly attracted to plant roots and cause a slow decline of the roots and cause a slow decline of the plant.plant.

They also can infect fungi and can form They also can infect fungi and can form symbiotic associations with bacteria.symbiotic associations with bacteria.

Roundworm parasites of other Roundworm parasites of other organismsorganisms

Nematodes also can be used to control pests.Nematodes also can be used to control pests.

Echinoderms have varied nutritionEchinoderms have varied nutrition

All echinoderms have a mouth, stomach, and All echinoderms have a mouth, stomach, and intestines, but their methods of obtaining food intestines, but their methods of obtaining food vary.vary.

Sea stars are carnivorous and prey on Sea stars are carnivorous and prey on worms or on mollusks such as clams.worms or on mollusks such as clams.

Echinoderms have varied nutritionEchinoderms have varied nutrition

Most sea urchins are herbivores and graze on Most sea urchins are herbivores and graze on algae.algae.

Brittle stars, sea lilies, and sea cucumbers Brittle stars, sea lilies, and sea cucumbers feed on dead and decaying matter that drifts feed on dead and decaying matter that drifts down to the ocean floor.down to the ocean floor.

Most turtles and tortoises are too slow to be Most turtles and tortoises are too slow to be effective predators, but that doesn’t mean they effective predators, but that doesn’t mean they go hungry.go hungry.

Most are Most are herbivores, and herbivores, and those that are those that are predators prey predators prey on worms and on worms and mollusks.mollusks.

How reptiles obtain foodHow reptiles obtain food

Snapping turtles, however, are extremely Snapping turtles, however, are extremely aggressive, attacking fishes and amphibians, aggressive, attacking fishes and amphibians, and even pulling ducklings under water.and even pulling ducklings under water.

How reptiles obtain foodHow reptiles obtain food

Lizards primarily eat insects.Lizards primarily eat insects.

The Komodo dragon, The Komodo dragon, the largest lizard, is the largest lizard, is found on several found on several islands in Indonesia, islands in Indonesia, north of Australia. It north of Australia. It is an efficient predator, is an efficient predator, sometimes even of sometimes even of humans.humans.

How reptiles obtain foodHow reptiles obtain food

Snakes are also Snakes are also effective predators.effective predators.

Some, like the Some, like the rattlesnake, have rattlesnake, have poison fangs that poison fangs that they use to they use to subdue or kill subdue or kill their prey.their prey.

How reptiles obtain foodHow reptiles obtain food

How reptiles obtain foodHow reptiles obtain food

A constrictor wraps A constrictor wraps its body around its its body around its prey, tightening its prey, tightening its grip each time the grip each time the prey animal exhales.prey animal exhales.

Mammals, Mammals, like birds, like birds, are are endotherms.endotherms.

What is a mammal?What is a mammal?

Mammals with teeth Mammals with teeth have different kinds have different kinds that are adapted to that are adapted to the type of food the the type of food the animal eats.animal eats.

Most mammals have specialized teethMost mammals have specialized teeth

The pointed incisors of moles grasp and hold The pointed incisors of moles grasp and hold small prey.small prey.

The chisel-like incisors of beavers are The chisel-like incisors of beavers are modified for gnawing.modified for gnawing.

Most mammals have specialized teethMost mammals have specialized teeth

A lion’s canines A lion’s canines puncture and puncture and tear the flesh of tear the flesh of its prey.its prey.

Most mammals have specialized teethMost mammals have specialized teeth

Most mammals have specialized teethMost mammals have specialized teeth

Premolars and molars are used for slicing or Premolars and molars are used for slicing or shearing, crushing, and grinding.shearing, crushing, and grinding.

Many hoofed mammals have an adaptation Many hoofed mammals have an adaptation called cud chewing that enables the called cud chewing that enables the cellulose in plant cell walls to be broken cellulose in plant cell walls to be broken down into nutrients they can absorb and use.down into nutrients they can absorb and use.

When plant material is swallowed, it moves When plant material is swallowed, it moves into the first two of four pouches in the into the first two of four pouches in the stomach where cellulose in the cell walls is stomach where cellulose in the cell walls is broken down by bacteria.broken down by bacteria.

Most mammals have specialized teethMost mammals have specialized teeth

The partially digested food, called cud, is The partially digested food, called cud, is repeatedly brought back up into the mouth.repeatedly brought back up into the mouth.

Most mammals have specialized teethMost mammals have specialized teeth

After more chewing, the cud is swallowed again After more chewing, the cud is swallowed again and when the food particles are small enough and when the food particles are small enough they are passed to the other stomach areas, they are passed to the other stomach areas, where digestion continues.where digestion continues.

Most mammals have specialized teethMost mammals have specialized teeth