Seeing : Earthworms have no eyes, but they do have light receptors and can tell when they are in the dark, or in the light.
Why is being able to detect light so important to a worm? Hearing : Earthworms have no ears, but their bodies can sense the vibrations of animals moving nearby. Thinking and feeling : Worms have a brain that connects with nerves from their skin and muscles. Their nerves can detect light, vibrations, and even some tastes, and the muscles of their bodies make movements in response. Breathing : Worms breathe air in and carbon dioxide out, just like us, but they don't have lungs.
They can't breathe through their mouth, and certainly can't breathe through their nose because they don't even have one! They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe. If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
The movements of the worm's body make the blood flow back to the back end of the body, and the hearts pump the blood forward again. Carbon dioxide dissolves out of the blood back to the skin. Eating : Worms do not have teeth, but their mouths are muscular and strong. Nightcrawlers can even pull leaves into their burrows using their strong mouths. The front end of the worm, its prostomium , is pointed and firm, making it easy for worms to push their way into crevices as they eat their way through their burrows.
The mouth of the worm is just behind the prostomium. Worms swallow pieces of dirt and decaying leaves, and the food passes through the pharynx , located in body segments , the esophagus segments , and into the crop, which stores food temporarily.
The worm's stomach is very muscular, so is called a gizzard. They allow earthworms to detect light and changes in light intensity.
Instead they use oxygen that is dissolved in the moisture on their skin and from the surrounding environment.
Earthworms cannot hear but they can sense vibrations. Reproduction Mature earthworms have a clitellum or a saddle. The size, shape, colour and position of the clitellum varies between species. The clitellum means the earthworm is an adult and is ready to mate and lay eggs. Earthworms reproduce by forming a small egg sac — called a cocoon — at the clitellum. Adaptation is an evolutionary process whereby an organism becomes increasingly well suited to living in a particular habitat.
Natural selection results in helpful traits becoming more common in a In this activity, students use observation to explore earthworm anatomy and the nature of science. By the end of this activity, students should be able to: identify various physical When you look at the world around you, how do you categorise or group what you see?
One of the broadest groupings is 'living' and 'non-living'. This may sound simple, but it is sometimes Add to collection. Rights: University of Waikato. However, the fluid inside the segments helps prevent damage to the earthworm. Fluid cannot change volume because the molecules in the fluid are very close together. To move forward, circular muscles in the front of the body contract. Contracting those muscles makes the segments thinner and longer, allowing the worm to reach forward.
The earthworm also relies on anchors, called setae, which are short stiff hairs that can hold onto the soil. Setae extend out of the skin and hold the front of its body to the soil. Once anchored, longitudinal muscles in the front of the body contract. Contracting those muscles makes the segments shorter and fatter. The front of the body shortens, pulling the back of the body forward. Then setae from the front of the body retract and the setae in the back of the body anchor to the soil.
The process repeats itself as the earthworm makes its way through the soil. The movement of the earthworm is wave-like, as muscles take turns lengthening and then shortening. To watch a video of an earthworm in action, see this video from Encyclopedia Britannica, or the video from Shape of Life embedded below.
This video from Shape of Life discusses the ecological role of earthworms as decomposers and demonstrates how they move and burrow. An earthworm has a special ability to crawl through tight spaces. Humans have designed robots to mimic this crawling motion. These robots could be made to burrow deep underground and distribute materials or test underground conditions quickly without the need to dig large holes. Contraction of circular, radial or transverse muscle fibers will decrease the diameter, thereby increasing the pressure, and because no significant change in volume can occur, this decrease in diameter must result in an increase in length.
Following elongation, shortening can be caused by contraction of the longitudinal muscle fibers, re-expanding the diameter and thus re-elongating the circular, radial or transverse muscle fibers. Invasive Species Compendium. Maggots scrape dead tissue with mouth hooks then spew a stew of enzymes to liquefy, swallow, and digest it. Fungi create a strong but lightweight material by producing a random network of tiny threads.
Three muscle fiber patterns inside trunks work together to provide the strength, support, and resistance needed to bend and twist with extreme agility. The shell of a tortoise withstands pressure through interlocking scutes of various shapes consisting of both rigid and flexible layers. A combination of mineral crystals and collagen fibers protects bone from major fractures by sacrificing small structural elements.
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