MR. SQUIRMY'S DISSECTION
Jackson Hardin Vu-PAP Bio-4
MR. SQUIRMY'S LIFE STORY AND INFORMATION
- Describe the apperance of various organisms found in the earthworm.
- Name the organs that make up various systems of the earthworm.
- Mr. Squirmy has another name besides "Mr. Squirmy". He also goes by Lumbricina.
- He lives at or under the surface of the soil. Lumbricina tends not to live in exceptionally dry or cold places.
- Mr. Squirmy improves soil wherever he is present by providing a natural means of aeration. As he moves through the ground, he create tunnels. Air and water then pass through these tunnels to the roots of plants. They break down organic matter such as leaves and litter and excrete nitrogen-rich waste that fetilizes the soil.
- Unfortunantly Mr. Squirmy is not friends with robins, weasels, otters, mink, frogs, pigs, raccoons, woodscocks, turtles, toads, fishermen, biology students etc. for obvious reasons
- Lumbricina need to sustain their macho apperance so they comsume manly things like soil, decaying roots, leaves, bacteria, fungi, etc.
- Mr. Squirmy has definetly had evolutionary adaptions including his sensitivety to vibrations and secreting a mucus to help him move easier through the soil. Other adaptations including its pharynx to help him eat his food.
The largest earthworm ever found was in South Africa and measured 22 feet from its nose to the tip of its tail!
LETS EXPLORE MR. SQUIRMY'S DIGESTIVE TRACT
Worms do not have teeth, but their mouths are muscular and strong. They can even pull leaves into their burrows using their strong mouths. The front end of the worm is pointed and firm, making it easy for worms to push their way into crevices as they eat their way through their burrows.
Like a bird's gizzard, it grinds up the food, which then moves into the intestines. In the intestine, food is broken down into usable chemicals which are absorbed into the bloodstream. Leftover soil particles and undigested organic matter pass out of the worm through the rectum and anus in the form of worm poop. Worm poop is dark, moist, soil-colored, and very rich in nutrients. That's why farmers and gardeners like to have lots of worms in their soil.
Pharynx, Esophagus, Crop and Gizzard
Worms swallow pieces of dirt and decaying leaves, and the food passes through the pharynx, the esophagus and into the crop, which stores food temporarily. The worm's stomach is very muscular, so is called a gizzard.
MR. SQUIRMY'S ECOLOGY
Earthworms are divided into four groups, called ecotypes, each of which has a different life style.
As their name would suggest, these are most likely to be found in a compost bin. They prefer warm and moist environments with a ready supply of fresh compost material. They can very rapidly consume this material and also reproduce very quickly. Compost earthworms tend to be bright red in colour and stripy.
Epigeic earthworms live on the surface of the soil in leaf litter. These species tend not to make burrows but live in and feed on the leaf litter. Epigeic earthworms are also often bright red or reddy-brown, but they are not stripy.
Endogeic earthworms live in and feed on the soil. They make horizontal burrows through the soil to move around and to feed and they will reuse these burrows to a certain extent. Endogeic earthworms are often pale colours, grey, pale pink, green or blue. Some can burrow very deeply in the soil.
Anecic earthworms make permanent vertical burrows in soil. They feed on leaves on the soil surface that they drag into their burrows. They also cast on the surface, and these casts can quite often be seen in grasslands. They also make middens (piles of casts) around the entrance to their burrows. Anecic species are the largest species of earthworms in the UK. They are darkly colored at the head end (red or brown) and have paler tails.
TAXONOMY OF MR. SQUIRMY
Scientific name: Lumbrucis terrestris
If a worm’s skin dries out, it will die!
Mr. Squirmy's Evolution
- Each segment on an earthworm’s body has a number of bristly hairs, called setae. These hairs provide some grip to help the earthworm move through the soil.
- An earthworm has a streamlined body with no antennae or fins or arms or legs! This streamlined shape is an adaptation to living in narrow burrows underground and the need to move easily through the soil.
- An earthworm has circular muscles that surround each body segment. It also has longitudinal muscles that run the length of its body. These two groups of muscles work together to help the earthworm move.
- In order to get food into its mouth, an earthworm pushes its pharynx out of its mouth to grasp hold of its food. It then pulls the food back into its mouth and wets it with saliva.
- Many earthworms secrete a mucus that helps them to move more easily through the soil. In some burrowing species, this fluid forms a cement-like substance that lines their burrows to help keep the walls from collapsing.
- When the environmental conditions in an earthworm’s habitat change, for example, the soil becomes too hot or too dry, many earthworms become inactive in a process called aestivation. They move deeper into the soil, coil into a tight ball, excrete a protective mucus and lower their metabolic rate in order to reduce water loss. They will remain like this until conditions become favourable again.
- Earthworms cannot see or hear but they are sensitive to vibrations. Birds looking for food or humans collecting earthworms for bait stamp on or vibrate the ground in some manner, causing earthworms to move to the surface. Perhaps this is to escape from moles, whose primary food is earthworms.
- Earthworms are sensitive to light. Most species spend their days in their burrows or in the soil or leaf litter. In general, you usually find them on the surface at night.
- Earthworms lose moisture through their skin. They move out of their burrows to migrate or reproduce when the ground is wet with dew.
POPULATION DYNAMICS FOR MR. SQUIRMY'S SPECIES