Earthworm Facts

Earthworm Facts
Earthworm belongs to the group of invertebrates. It has soft body, shaped like tube. There are around 6000 species of earthworms that are native to Europe. They are widely distributed in the Asia and North America today. Earthworms inhabit moist soil. These animals are very important because they increase fertility of the soil and represent important part of diet of numerous animals in the wild. Earthworms are even consumed as delicacy in certain parts of the world. Species of earthworms that live on the farmlands are often victims of the chemical pollution (pesticides). Other species of earthworms are numerous in the wild.
Interesting Earthworm Facts:
Size of earthworm depends on the species. They can reach 14 inches in length and 0.39 ounces of weight.
Earthworms have segmented body that is usually reddish-brown in color.
Earthworms do not have skeleton. Liquid (called coelomic fluid) fills inner part of the worm’s body and provides shape and structure.
Earthworms breathe through their skin.
Specialized cells on the body of earthworm secrete mucus which moisturizes the skin. Moist skin facilitates movement and breathing.
Each segment on the body of earthworm contains group of bristles (called setae) which are used for movement. Earthworms move in a wave-like manner as a result of contractions of longitudinal and circular muscles located inside the worm’s body.
Earthworms are able to regenerate missing part of the body as long as clitelum (swollen area in the first half of the body) and 10 segments behind it are intact.
Diet of earthworms consists of dead (decaying) organic matter and live organisms such as fungi, protozoa, nematode and bacteria.
Earthworms are beneficial for the soil because they dig tunnels (which facilitate aeration) and transfer nutrients from deeper layers of the ground to the surface.
Fertile soil can contain up to 432 earthworms per square meter.
Earthworms are important part of the food chain. Many types of birds, mammals, lizards, snakes and frogs eat earthworms as a regular part of their diet.
Earthworms are hermaphrodites, which mean that each earthworm contains both male and female reproductive organs. Despite that, earthworms require partner for mating with whom they exchange packages of sperm.
Belt-like swollen area on the earthworm’s body is called clitelum. It secretes slimy substance that forms capsule which protects eggs (sperm cells and eggs merge inside the capsule and form embryos). Encapsulated, lemon-shaped structure with eggs is called cocoon.
Earthworms produce 3 to 80 cocoons per year. Each cocoon contains from 1 to 20 fertilized eggs. Development of eggs depends on the environmental conditions (moisture, temperature, acidity of the soil…). It usually takes 60 to 90 days for earthworms to hatch.
Earthworms reach maturity after 10 to 55 weeks and live from 4 to 8 years in the wild.

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