New Zealand earthworm facts for kids

The Octochaetus multiporus, also known as the New Zealand earthworm, is a special worm found only in New Zealand. It's a type of earthworm that lives mainly in the south of Manawatu on the North Island, but you can also find it along the east coast of the South Island. This amazing worm can glow in the dark! When it feels scared or gets hurt, it squirts a glowing liquid from its mouth.

What is the New Zealand Earthworm?

This unique worm was first described by a scientist named Frank Evers Beddard in 1885. It's the main example for a group of earthworms called Octochaetidae. Most worms in this family live in places like Australia and New Zealand. Scientists recently found a "missing link" worm, Octochaetus ambrosensis, which connects the worms in New Zealand to those in India.

What Does the New Zealand Earthworm Look Like?

The Octochaetus multiporus is usually a pale pink color. Its body wall is see-through, and it has a purple stripe running down its back. This worm can grow quite long, up to 300 millimeters (about 12 inches), and be about 10 millimeters (0.4 inches) wide.

Identifying Features

A special part of the worm's body, called the clitellum, helps scientists identify it. The clitellum is a glandular section that holds the worm's eggs. For the New Zealand earthworm, this part is usually found on segments 14 to 19 of its body.

The New Zealand earthworm has strong muscles at its head (front) and tail (back) ends. These muscles help it burrow easily through the soil. This ability is important for improving the soil in pastures and native woodlands.

Where Does the New Zealand Earthworm Live?

Octochaetus multiporus is endemic to New Zealand. This means it naturally lives only in New Zealand and nowhere else in the world. It is one of the most common native earthworm species in New Zealand. Other related species in its family can be found in India and Australia.

Preferred Habitats

You can mostly find O. multiporus in the pasturelands of southern Manawatu on the North Island. They also live along the east coast of the South Island and on Stewart Island. These worms prefer the subsoil of New Zealand's native forests, tussock lands, and pasturelands. They thrive in areas that haven't been harmed by deforestation or chemical pollution. Native forests are their natural home.

These earthworms are found in larger numbers in soils that slope away from the sun. This helps keep the soil well-ventilated and moist, which is perfect for them. O. multiporus are most common in soils with low to moderate fertility.

Temperature Needs

Earthworms, including O. multiporus, have a very small temperature range where they can live comfortably. The best temperature for most earthworms is around 20°C (68°F). They can be in danger if temperatures reach 25°C to 30°C (77°F to 86°F).

Life Cycle and Ecology

Even though O. multiporus is very common and has been studied a lot, scientists still don't know everything about its full life cycle.

What Do They Eat?

Earthworms eat dead and decaying plant matter in the soil, like roots and leaves. As they eat, they help to aerate the soil (add air to it) and break down organic material. This process creates a very valuable type of fertilizer called worm castings.

The best soils for O. multiporus are in the Southern Manawatu Region, the east coast of the South Island, and Stewart Island. This worm relies less on native plants for food compared to some other native worms.

Who Eats the New Zealand Earthworm?

In New Zealand, the main animals that eat earthworms are introduced bird species. These birds live in the same pasturelands as O. multiporus. Some of these birds include gulls, starlings, and magpies. These birds were brought to New Zealand by humans.

In the native forests of New Zealand, O. multiporus is an important part of the kiwi bird's diet. Kiwis search the forest floor for bugs and worms in the soil.

Worm Health

Scientists have researched what tiny organisms, like bacteria, fungi, and mites, might live on or harm earthworms. However, not much is known about how much harm these organisms actually cause to the worms.

How Do Earthworms Help Humans?

Earthworms are very important for New Zealand's farming and native forest systems. They do a vital job by improving the soil structure. This is especially helpful in summer when pastures are moist and there aren't many introduced earthworms around.

O. multiporus is also very interesting to scientists because of its unique way of defending itself. When it feels threatened, this worm squirts a glowing fluid from its mouth. This glowing fluid can change color, from blue to yellow or orange, which can even show how mature the worm is. Besides releasing this fluid, the worm itself can also glow!