By Leighanne Masri
Vu - PAP Bio - Per.4
Lab Dissection Pictures!
In this presentation you will learn:
- All about Earthworms
- External and internal anatomy
- Interesting facts
- Body systems
- Key information
Background Information/ Ecology
- Setae (bristly hairs on body), provide grip
- Streamlined body, move easily underground
- Circular and longitudinal muscles, help with movement
- Pushes pharynx out of mouth, used to obtain food
- Secrete a mucus (coelomic fluid), helps move through soil
- Aestivation (short hibernation), helps with survival in extremes
Niche [Human Relations]
- Aerate soil
- Sustain agriculture by enriching soil
- Provide food for birds, snakes, and insects
- Recycle organic matter
- Increase nutrient availability
Body System Focus
- Mouth: Food enters through the mouth.
- Pharynx: The pharynx acts like a suction pump and the pharyngeal glands secrete mucus.
- Esophagus: In the esophagus calcium is pumped to maintain proper blood calcium levels in the blood and food pH.
- Crop: The crop stores food until ready for the gizzard.
- Gizzard: Stones consumed by the worm are used, along with muscles, to grind the food.
- Intestine: The intestine releases fluid to help digest. The walls of the intestine contain blood vessels where the digested food is absorbed and transported to the rest of the body.
One other body system of an earthworm is the circulatory system. The circulatory system in composed of three main vessels: aortic arches, dorsal blood vessels, and ventral blood vessels. All of these are connected with the digestive system. The blood vessels run down the intestine, and the aortic arches wrap around the esophagus.
- About 2,700 kinds of earthworms
- 1 acre/ 1 million+ worms
- Largest earthworm: 22ft
- Charles Darwin spent 39 years studying earthworms
- Worms are cold-blooded animals
- Possess the ability to replace/replicate lost segments
- Worms don't have eyes, but can sense light
- Worms become paralyzed if over-exposed to light
- If an earthworm's skin dries out, then it dies
- Worms can eat their weight daily
- Worms are hermaphrodite, possessing both male and female organs