The Zone Without A Backbone

There are three different kinds of worms;

Flatworms,

Roundworms,

and Segmented Worms.

Phylum:

• Flatworms are from the phylum Platyhelminthes.

Habitat:

• Flatworms can live in oceans, freshwater ponds, on land, and even inside another animal.

Nervous System:

• Flatworms' nervous systems are far more advanced than that of cnidarians. Flatworms have developed a head, a brain, and eyes.
• The head and brain was a centralized nervous system, which was much more advanced than cnidarians' nerve nets.
• The eyes were primitive, however. They could only sense the light's direction and intensity.

Movement:

• Flatworms move by making a bed of slime, then crawling over it with cilia.

Hunting:

• Flatworms are good hunters because their eyes and senses can tell them where their prey is going.
• They were also flat and free-moving so they were faster and able to chase after their prey.

Reproduction:

• Flatworms can reproduce two ways. Since they are hermaphrodites, they can split in half, this is called regeneration. They also have sperm and eggs in every segment so when the eggs are fertilized, they can just break off of the segment.

Different Types:

• There are two different types of flatworms, planarians and tapeworms.
• TAPEWORMS: tapeworms are parasitic. They attach themselves to the inside of an animal's intestine with hooks and suction cups. Then they just absorb the nutrients from the other animal's intestine. Tapeworms don't have digestive systems because the food that they are getting is already digested.
• PLANARIANS: planarians are scavengers, which means that they eat dead things. They are carnivores/ predators. They are faster than their prey, so when they catch up to it, they slide on top of it, lower the pharynx on the middle of it, then start sucking the animal up through its straw-like pharynx.

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Phylum:

• Roundworms are in the phylum Nematoda.

Habitat:

• Roundworms can live in any moist environment, but they can't live underwater.

Digestive System:

• Roundworms have two bodily openings; the mouth and the anus. This makes a tube-like digestive system.
• Roundworms digestive system is efficient because they can constantly eat, not eat, "throw up" their waste, then eat again. They can absorb more nutrients from their food because they have a long intestine. They have organs that have their own functions.

Examples:

• One example of a round worm is the heartworm.

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Phylum:

• Segmented worms are from the phylum Annelida. Segmented worms are the most known worms to humans.

Movement:

• Earthworms are able to move because of their segments. They compress some segments while stretching others.

Feeding and Digesting:

• Earthworms eat soil and they get energy from organic matter.
• An earthworm's digestive system contains a mouth, esophagus, crop, gizzard, intestine and anus. Mouths allow the food to enter, the esophagus transports the food to the crop, the crop stores food, the gizzard grinds food, the intestine absorbs nutrients, and the anus gets rid of it.

Circulatory System:

• Earthworms have a closed circulatory system, their blood moves quickly so that animal can be large ad active.
• These worms have two blood vessels, the dorsal and the ventral blood vessels.
• They have 5 hearts.

Respiratory System:

• They do not have any lungs or gills, so they have to breathe through their skin.

Nervous System:

• Earthworms have a small brain, which is connected by a ventral nerve cord.

Stimuli:

• They respond to touch, temperature, light and moisture.

Examples:

• Some examples of segmented worms are earthworms, leeches, polychaetes.

Yay Wormies!! 

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