Quck answer
Earthworms are segmented worms that play a vital role in maintaining soil health. They feed on decaying organic matter and help break it down, making nutrients available to plants. Earthworms also help to aerate the soil, allowing air and water to penetrate deeper. They have a simple circulatory system, with blood vessels running along the length of their body. Earthworms have both male and female reproductive organs, but they still need to mate with another worm to reproduce. They are sensitive to light and vibrations, and will retreat underground if threatened. In short, earthworms are important soil engineers that contribute to a healthy ecosystem.
Animal Information
The Life Cycle and Survival of the Common Earthworm
Apart from moles, earthworms have to evade many other predators and tolerate various parasites throughout their lives.
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Depending on the species, earthworms have varying life expectancies from the time they emerge from cocoons until they die. The night crawler typically lives between six to nine years and has been known to survive for up to 20 years [source: Backman]. Red worms, on the other hand, have an average lifespan of two to five years [source: Wormman.com]. Gray worms, which spend their entire lives underground, usually live between 1.25 and 2.6 years on average [source: Muratake].
During their lifetimes, earthworms develop preferences for food and habitats, and they demonstrate a need for continually moist environments, with humidity levels ranging from 50% to 90%. They are also sensitive to temperature changes above ground and are most active between 59 and 86 degrees Fahrenheit (15 to 30 degrees Celsius) [source: Edwards]. Although earthworms consume a variety of organic matter, from protozoa to leaves to animal corpses, they have dietary preferences. Researchers discovered that earthworms prefer maple leaves to oak leaves and clover to grass. In an experiment, only 0.6% of clover residue remained uneaten, while 9% of grass remained [sources: WSU, Bugg].
Therefore, earthworms can thrive in any location that is relatively warm, moist, and abundant in food, from Wisconsin forests to sewage treatment plants in Malaysia. When these conditions are not adequate, earthworms may enter a dormant state until they improve. In this dormant state, known as aestivation, they stop living, do not require food, movement, or reproduction, and instead curl up in a ball to preserve skin moisture until conditions improve [source: Southwest Wildlife].
Throughout their lives, earthworms must avoid numerous natural predators. In addition to birds and moles, earthworms must also beware of foxes, hedgehogs, turtles, slugs, beetles, snakes, and leeches, all of which enjoy feeding on them. Additionally, they may harbor several parasites that can infect humans, such as nematodes, mites, and flatworms, as well as cluster flies that lay their eggs in earthworm burrows. When the eggs hatch, the maggots parasitically attach and feed on the earthworm [source: Tomlin].
FAQ
1. What are earthworms and why are they important?
Earthworms are invertebrate animals that live in soil and play a crucial role in maintaining soil fertility. They are important decomposers, breaking down dead organic matter and turning it into nutrient-rich soil. Earthworms also help to aerate the soil, allowing water and air to circulate more effectively. This is beneficial for plant growth and helps to prevent soil erosion.
2. How do earthworms move through soil?
Earthworms move through soil by contracting and relaxing their muscles, which creates a wave-like motion that propels them forward. They also secrete mucus to help reduce friction against the soil and make movement easier. Earthworms can move through soil relatively quickly, with some species able to travel up to 40 feet in a day.
3. How do earthworms digest food?
Earthworms have a unique digestive system that allows them to digest both organic and inorganic matter. The food enters the worm’s mouth and travels through the pharynx, esophagus, crop, gizzard, and intestine. In the gizzard, the food is ground up by muscular contractions and small stones that the worm has ingested. The intestine then absorbs nutrients from the food, and the waste is excreted as castings.
4. How do earthworms reproduce?
Earthworms are hermaphrodites, which means they have both male and female reproductive organs. During mating, two earthworms exchange sperm, and then each worm forms a cocoon around its own eggs and sperm. The cocoon is then deposited in a moist location, where the eggs will hatch and the baby earthworms will grow until they reach maturity.
5. What are the different types of earthworms?
There are over 7,000 different species of earthworms, but the most common types are the nightcrawler, red wiggler, and brandling worm. Nightcrawlers are large and are often used for fishing bait. Red wigglers are smaller and are commonly used for composting. Brandling worms are also used for composting and are known for their distinctive striped appearance.
6. Can earthworms survive outside of soil?
Earthworms are adapted to life in soil and are not able to survive for long periods of time outside of it. They require moist conditions and a steady supply of organic matter to feed on. If they are exposed to dry conditions or a lack of food, they will become stressed and may die. It is important to provide earthworms with a suitable habitat if you are keeping them for composting or other purposes.
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