The earthworm primer

Q. Can you do an article about earthworms? I’ve always been interested in how they do what they do.

Joe from Canfield

A. We have done articles on the role they play in our gardens, but we now look at them. The typical earthworm Lumbricus terrestris is basically a tube within a tube.

Let’s start with locomotion. Long muscles running the entire length push the body forward, and round segments of the entire body pull it along.

The body secretes mucus to keep moist, to help movement and to breathe. They have no eyes but photosensitive cells are distributed the entire body concentrated in the head, along the back, and sides. (Wouldn’t that be a cool thing to have!) Setae (S-shaped hairs) on the sides of the body act like anchors and move the body along.

The digestive system is a tube running the length, with a mouth and “lip” (prostomum) that covers the mouth and acts like a wedge to push through soil.

The pharynx is where soil is lubricated. The esophagus carries the mixed food to the gizzard (like birds) where sandy mix grinds soil. The intestine carries this mix and digests needed nutrients, and the anus excretes wastes called casts.

Worms breathe through their skin, and circulatory system carries oxygen and gases as well as nutrients for the entire body.

Their body must be moist at all times for respiration to take place. All is controlled by a rudimentary nerve center – the brain – of periphery nerves.

Reproduction is a fascinating thing when it comes to earthworms.

First, worms are hermaphroditic, meaning they are both sexes, but they must mate with each other to produce offspring.

Beginning on a warm, wet spring night the worms congregate and pick a mate. They lie next to each other head to tail. The white band on their bodies turns red, and secretes mucus to bind the two. This is copulation. Then sperm is exchanged.

As the two back out of the mucus tube, the eggs are fertilized and implanted in the tube. When they pull out, the tube is sealed in an onion-shaped cocoon. Inside is the precious offspring. They can produce 20 to 30 cocoons per year.

All in all, the lowly earthworm is an incredible work of science. You can learn about them at: http://go.osu.edu/earthworm

Stephanie Hughes is an OSU Extension master gardener volunteer in Mahoning County. The clinic is now open for spring. Call 330-533-5538 to submit your questions. Regular clinic hours are 9 a.m. to noon Mondays and Thursdays.