There are literally hundreds of thousands of worm species in the world today and roughly 2,700 are earthworms. Although there are thousands of different species of worms around the world, worms share a number of common characteristics. Their physical characteristics are similar as well as their diet, reproduction, where they live, and defense mechanisms.
Worm Physical Characteristics
For starters, worms have no lungs. This means, they breathe through their skin, so the worm’s environment and the worm’s skin must be moist at all times. This allows the worm to breathe in oxygen. While the sand may be moist and wet closer the water, the majority of the sand is dry. If the worm’s skin dries out, the worm will die from suffocation. In addition, too much moisture can also be detrimental to worms. If too much water is present, it takes the place of oxygen, which will cause the worm to flee to the surface. Once on the surface, worms will be exposed to sunlight. If the worm remains in the sunlight for too long, it can become paralyzed.
Believe it or not, worms do have mouths. Their mouths are actually big enough ad powerful enough to grab a leaf and drag it around. They also have a pharynx, esophagus, crop, gizzard and intestine. When the worm eats its food, it pulls the materials into its mouth with the help of the pharynx and its prostomium (also called acron). This creates a suction motion. This suction motion aids in helping the worm consume large amounts of food in a sort amount of time. The gizzard grinds the food. Worms eat so much that they typically produce excrement equal to their own weight every 24 hours.
Worms must remain close to their food supply, which consists of leaves and dead grass. Leaves and dead grass contain organisms that provide a healthy diet of bacteria, algae, and fungi to the worm. Worms feast on dirt as well, especially if they live deeper inside the earth. Worms also eat plants, fruits, and vegetables.
When it comes to reproduction, the worm’s environment plays an extremely important role as well. Worms prefer to mate or reproduce in warm moist soil and away from light, of course.
Worm Defense Mechanisms
Worms protect themselves from the elements by burrowing deep into the earth. This is also a way to protect itself from predators such as birds and larger insects. Worms also protect themselves by grabbing onto the soil with the tiny bristles located on each of their segments. Earthworms may also coil themselves as a defense mechanism. It is important to keep in mind that coiling is also a part of mating.
The Aquatic Worm
The aquatic worm, a close relative of the earthworm, lives in the water instead of in the ground. They can live just about anywhere that has fresh water. This includes streams, lakes, marshes, and ponds. The aquatic worm prefers shallow water, so they are easy to spot. Aquatic worms have a large number of predators including leeches, turtles, ducks, aquatic insects, crayfish, young fish, and tadpoles. When the aquatic worm feels threatened by its predators, it will coil up to protect itself.