Earthworm and leech belong to the same phylum of Annelida. They both resemble worm-like creatures and they are hermaphrodites.
They two belong to different subclasses. Earthworms fall in subclass; Oligochaeta while leeches fall in subclass Hirudinae.
Both earthworms and leeches are useful and play vital roles. Earthworms play a vital role in agriculture while leeches are useful in traditional medicines.
So, what is the main difference between earthworms and leeches? The earthworm is thin, elongated, round in structure, and white in color while the leech is flat, short, and black in color.
For information about the differences between earthworms and leeches, read through this article. You will also get to learn more about their similarities.
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Comparison Table (Earthworm vs. Leech)
| Basic Terms | Earthworm | Leech |
| Body structure | It is thin, elongated, round in structure. | It is flat and short. |
| Color | It is white in color. | It is black in color. |
| Habitat | They mostly live in the soil. | They inhabit a wide range of habitats such as freshwater, marine, and terrestrial ecosystem. |
| Suction | Their pharynx act as a suction pump. | The suction disks are present on each end of the body. |
| What they feed on | They mostly feed on soil particles. | They feed on blood and sometimes eat small invertebrates. |
| Movement | They move through contraction and relaxation of body muscles that shorten and lengthen the body in order to move. | They move using anterior and posterior suckers and longitudinal muscles along the length of their body. |
| Benefit | They keep the soil aerated and fertile. | Some species are used as medicines. |
What is Earthworm?
Earthworm belongs to the subclass Oligochaeta under the phylum Annelida. There are around 6000 species found all over the world.
They have segmented tube-like bodies made of ring-like segments. The segments are connected by a gut, a nerve and blood vessels.
The mouth is located in the first segment of the body. They move through contraction and relaxation of body muscles that shorten and lengthen the body in order to move.
They are hermaphrodites as body male and female reproductive systems are found on their bodies. During mating, sperms are exchanged between two worms.
They do not have a respiratory system. They breathe through their skin. They are mostly scavengers. They feed on organic matter such as dead leaves and soil particles.
They absorb nutrients as the soil passes through their guts and excretes the soil. The droppings are called castings.
What is Leech?
Leech belongs to subclass Hirudinea under the phylum Annelida. They are about 700 species of leeches in the entire world. They are found in freshwater habitats and some live in salty water systems.
They are worm-like creatures with segmented bodies which are flattened dorsal ventrally and have suction disks on every end of their body.
The first segment is the head which contains the mouth with sharp cutting beaks located within the head sucker.
They move using anterior and posterior suckers and longitudinal muscles along the length of their body.
They are hermaphrodites as both the male and female reproductive systems are found on their bodies. During mating, the two leeches align themselves and inject sperms into each other.
They feed on blood and small invertebrates. They store a large volume of blood in their bodies before digestion starts. Their natural predators include fish, herons, shorebirds, and turtles.
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Main Difference between Earthworm and Leech
- Earthworms are thin, elongated, and round in structure while leeches are flat and short in structure.
- Earthworms feed soil particles and dead leaves while leeches feed on blood and small invertebrates.
- Earthworms are white in color while leeches are black in color.
- Earthworms live in the soil while leeches live in a wide range of habitats including freshwater, marine, and terrestrial ecosystem.
- Earthworms keep the soil aerated and fertile while some leech species are used as medicine.
- Earthworms move through contraction and relaxation of their body muscles while leeches move using anterior and posterior suckers found on their bodies.
- Earthworms have pharynx that acts as suction pumps while leeches have suction disks present on each end of the body.
Similarities between Earthworm and Leech
- Both belong to the same phylum.
- Both have segmented bodies.
- Both are worm-like creatures.
- Both are hermaphrodites.
Conclusion
Earthworms and leech belong to the same phylum known as Annelida. They both have segmented bodies and they are worm-like creatures.
However, the two are different from each other. The main difference between the two is that; earthworms are thin, elongated, and round in structure and they are white in color while leeches are short, flat and they are black in color.
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