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8 Unique Characteristics of Leeches

Leeches are primarily known for being parasites and bloodsuckers, but they are actually one of the most fascinating animals on the planet. Leeches are mostly aquatic creatures that live in freshwater environments, there are over 1000 species found worldwide. This article will go over some interesting characteristics of leeches.

What Is A Characteristic?

A characteristic is something that distinguishes a person, animal, or thing. There are two kinds of characteristics: behavioral and physical.

Behavioral characteristics are the things an animal does that distinguish it from others, such as how it lives, moves, or reproduces. On the other hand, physical characteristics differentiate an animal, such as eye color, height, or weight.

8 Characteristics of leeches

A leech’s head has suckers that allows it to attach itself to fish and other animals so it can drink blood from this host. Here are some lesser known characteristics of leeches.

1. Have 34 body segments

Leech on white table
Leech on white table

Leech segmentation is a distinct feature of their anatomy. The body is divided into many segments, which are usually 33 or 34.

Each of these segments has its own organs that work together to ensure the survival of this species. Leeches also have flattened bodies, which allows them to stay on the side of rocks and fit into small crevices where they can hide from predators.

2. Poor eyesight

The leech has 10 eyes. But despite this, its vision isn’t particularly good. Their eyes have 50 photoreceptors arranged in five pairs at the anterior end.

Since they have poor vision, they’ve created a system in which each eye sends signals to the brain whenever it detects light (or movement). This enables the leech to locate its prey even when it can’t see it clearly.

They also have chemical receptors and sensory organs that enable them to track their prey by sensing their movement and any changes in their surroundings.

3. Have suckers

Leeches on human skin
Leeches on human skin

Leeches are worms and have no legs, so they can’t walk or run. However, these worms have a unique way of moving forward and swimming.

Each end of a leech’s body has a sucker that helps move forward. It travels like an inchworm by using its suckers to push the body forward. As for swimming, they move like an eel in the water to move in any direction they want.

4. Have 2 hearts, 32 brains and 10 stomachs

Leeches’  two hearts, 32 brains, and ten stomachs are also among the things that make them one of the most fascinating species on the planet.

Because of this, leeches can store large amounts of blood in their stomachs before digesting, and studies even show that their central nervous system can fully repair after injury.

5. Bloodsuckers

Leech sucking blood
Leech sucking blood

Leeches are best known as bloodsuckers, which is a behavioral characteristic where they use their suckers with tiny teeth to bite into a host’s skin and then suck up blood.

In fact, they’re known as predatory worms because they attach themselves to animals and can cause death if too many are attached to one and remain connected for too long. There are, however, some leech species that are used in medicine.

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Humans use these leeches to help with blood circulation when there is blood congestion or injury. They also have a painless bite, which causes animals, including humans, to be unaware that they have a leech attached to them.

6. Hermaphroditic

Leeches are hermaphrodites, meaning they have both male and female reproductive organs. They have four to ten pairs of testes that produce sperm and deposit them in the clitellar area of other leeches. These creatures mate by intertwining their bodies and depositing sperm into each other’s ovaries.

Fertilization will occur after this, and eggs will be released and deposited in a cocoon made of thick gelatin that they bury or attach to a rock, usually in damp soil.

7. Can reach 16 inches in length

Leech isolated on white
Leech isolated on white

If you’ve ever seen a leech, you’ll know that they’re usually about an inch long. However, these tiny creatures can grow to be 16 inches long.

The kind of species, habitat, and environment in which they live all affect their size and growth. Leeches from tropical regions are known to grow larger than other types of leeches.

This extraordinary creature also grows by molting, which means it sheds its skin and grows a new one. They shed every 3-10 days and grow through it by removing the molted skin with wavelike contractions.

8. Freshwater, terrestrial and marine animals

Terrestrial leech on coastal
Terrestrial leech on coastal | image by Ryan Wick via Flickr | CC BY 2.0

Leeches are a diverse group of animals that can live in a variety of habitats, such as freshwater, terrestrial, and marine environments. Freshwater leeches are typically found in areas with slow-flowing waters, and the majority of them fall into this category.

Terrestrial leeches are commonly seen on the ground, usually on wet forest floors, but the majority of them can’t swim. The last group is marine leeches, which live in saltwater environments. These leeches feed on fish and other aquatic animals, such as turtles, and spend most of their lives attached to them.