Annelids (segmented worms)


Marine Worms


A.Organized Body Made of One or More Cells - D'Shaun S

Segmented Worms are multi cellular. The worms have a organ system.
Segmented worms are long and narrow and they get their name because if you look at segmented worms body they have rings that circle their body. Their body can have over 100 rings which are called segments. The segments can be seen from the outside and inside of the body cavity. Each segment except for the first and last segments have four pair of setae which are the bristle-like structures that hold on to the soil. Their bodies have a front and back end and both ends are different. Segmented worms have two sets of muscles in the body wall. One set of muscle runs the length of the body while the other muscle circles the body.

There are more than 8,000 species of Marine worms. Marine worms, like earthworms, have segments with setea. However, the setea occur in bundles on the worm. Marine worms can also be called polychaetes which means "many bristles". Some Marine worms build tubes around their bodies, and when a Marine worm is startled they retreet into their tubes. Free swimming polychaetes such as the bristle worms have a head with eyes and tail and a parapodia (which are paired fleshy growth out of their segments).

Leeches are segmented worms but thier bodies are not as round or as long as earthworms and do not have setea. There is a sucker at each end of the leech's body and is used to attach to a animal.


B. Obtain and Use Energy - Josh Oikonomides
a worm eating dirt

Segmented worms eat tiny bits of dirt, very tiny rocks, rotting leaves, fruits and flowers. They also eat dead insects and dead decaying plants. Worms eat the bacteria off of dead plants and leaves. They also eat fungi and mold. They eat mold the same way we eat spaghetti by sucking it in their mouths. Worms eat mostly at night and when it's cool weather. They eat very little in the day. The food they eat is digested and turned into energy for their bodies.Leeches latch on to animals and humans and suck their blood out . Its very painful to remove a leech,they use leeches to reduce swelling from surgerys .

C. Reproduce - Josh Oikonomidesworms_mating[1].jpg

During the spring and summer when the weather is warm, segmented worms wiggle to the surface to mate. Each segmented worm needs a mate. Worms reproduce sexual. After mating, each segmented worm goes back into its own burrow. While in their burrow, each segmented worm, both male and female, give birth. When the weather cools later in the year, a ring like cocoon forms on the head of both male and female worms that have mated. Slowly the worm begins to move backward and the ring falls off and becomes an egg. Then the egg hatches soon after and about 2 worms come out.

D. Grow and Develop - Mackintyre G.

Earthworms create cocoons that contain fertilized eggs. It usually takes about 3 weeks for the eggs to hatch. When they hatch the earthworms are usually 1 inch long, and they are completely independent. They do not need their parent to take care of them. They just live on their own. Then in 6 weeks the baby earthworm matures into an adult earthworm. At that time it is winter and is very cold. The Earthworms go deep into the ground where the soil is warmer. Then they enter their warm season jobs and that is what they do in their adult life. In 4- 8 years in the earthworm's life, it eventually dies off.
This picture shows a adult earthworm.

E. Respond to Stimuli -Mackintyre G.

Earthworms, marine worms, and leeches respond to stimulus in the same sort of matter. The earthworm uses setae and 2 walls of muscle to move. It contacts its muscles that causes the segments to bunch up and the setae to stick, allowing the worm to be loose from the soil. When they flatten, the worm moves forward. The movement for a marine worm is similar for swimming. It also applies for leeches as well. The only difference is that leeches do not have Setae. Segmented worms respond to light, temperature, and moisture. Worms move away from the light because they know that the soil will dry out and they would not be able to move. They prefer moist soil so they won't dry out. They also live in warm soil. Since they are cold- blooded they need the warm soil for them to survive. That is why they go deep into the warm soil durig Winter.
As shown in the picture the segmented worm is turning from the light.

F. Exchange Gasses with the Envirorment- D'shaun

The worms can breath through their skin.The worms breath in oxygen and out carbon dioxide.
Worms do not have lungs. Insted they have skin cells that obsorebes oxygen and than pushes out carbon dioxide.

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Resources: D'Shaun-science explorer life science. life science. and off the internet.
Mackintyre wrote his awesome 2 paragraphs with the help of...
National Geographic Society; Biggs, Alton, et al. Life Science. New York: Glencoe McGraw-Hill, 2002.
Pfeffer, Wendy."Wiggling Worms At Work". New York: HARPERCOLLINSPUBLISHERS, 2004
French, Vivian."Yucky Worms". Shenzhen, Guangdong, China: Candlewick Press, 2009