Oligochaete facts for kids

Oligochaetes are a group of worms that belong to the phylum called Annelida. Think of them as a large family within the worm world!

There are about 10,000 different kinds of oligochaetes. This means they make up almost half of all the species in the Annelida phylum. The most famous oligochaete is probably the common garden earthworm you see wiggling in the soil.

Oligochaetes are known for having only a few "bristles" or hairs on their bodies. These bristles are called chaetae. This is different from another group of worms called polychaetes, which have many more bristles.

What Makes Oligochaetes Special?

Oligochaetes are segmented worms. This means their bodies are divided into many small ring-like parts, almost like a train with many cars. Each segment can move a little bit on its own.

Most oligochaetes have a special space inside their body called a coelom. This space is filled with fluid and acts like a "hydroskeleton." Imagine a water balloon – it's firm because of the water inside. The coelom helps the worm keep its shape and allows it to move by pushing against the fluid.

How Big Can They Get?

Oligochaetes come in many sizes. Some are tiny, less than half a millimeter long. You would need a magnifying glass to see them! Others are giant, like the Giant Gippsland earthworm from Australia or the Mekong Worm (Amynthas mekongianus). These giants can grow up to 2 to 3 meters (6.6 to 9.8 feet) long. That's as long as a small car!