Worms are truly amazing creatures. While they simply look like long tubes to you and me, they are wonderfully complex, with internal and external features that help them adapt to and interact seamlessly with their environment. In this blog post, we’ll be taking a closer look at the anatomy of the humble worm. You may be surprised at some of the facts we reveal below!
1- Worms have 5 hearts
The common earthworm has a heart and circulatory system like all animals – but it’s a lot simpler. They have five bulges in their main arteries. These can pump blood around their body. These act in the same way as our hearts, but they are much simpler and smaller. These five heart-like structures are spread evenly throughout their long bodies, to make sure the blood circulates efficiently.
2- Worms have no eyes, ears or teeth
Worms have no need to see or hear, as they spend most of their lives in the darkness of the soil. They have mouths at the top of their bodies. These small mouths are strong, with a powerful muscle that can break down their food before passing it into their digestive systems. This means they don’t need to bite. While they don’t have ears the way we understand them, earthworms are able to detect soundwaves through sensory neuron-like structures that are part of their skin. These vibrate in response to soundwaves, meaning they can listen through their skin!
3- Worms are hairy
While worms look smooth on the outside to the naked eye, they are covered with microscopic hairs or bristles. Known as setae, these bristles are arranged in bunches on each segment of the worm’s body. They create friction and have a gripping effect as the worm expands and contracts its muscles to move through the soil. This is needed to prevent the worm slipping backwards in the soil.
4- Worms have no lungs
Did you know worms don’t have lungs but can still breathe? Their bodies still take in oxygen and push out carbon dioxide like humans and other animals, but it’s done differently. They breathe through their skin. But they can only take in air if they are kept moist. A worm’s skin is coated with a layer of mucus, which aids oxygen intake. This is why it’s dangerous if worms dry out. The oxygen passes through their mucus, and into their bloodstream through the skin.
5- Worms have two layers of muscle
If you’ve ever wondered how worms manage to move through the soil so easily, they do so using two types of muscle that work in different ways. Their muscles are arranged in two layers. The top layer is made of circular muscles. Underneath are long muscles that run the entire length of the body. When the top layer contracts, the worm stretches out and becomes longer and thinner. The longer layer underneath contracts to make the worm shorter. This movement is what gets them through the soil and helps them to dig holes.
Here at Yorkshire Worms, we sell worms for a range of purposes, from gardening to fishing and composting. Take a look at our online live worm store to find out more.