About Leeches

Leeches are 'worms' with suckers on each end. Leeches can range in size from a half of inch to ten inches long. They are green, brown or black in colour. Some feed on decaying plant material. Others are parasites, feeding on blood and tissue of other animals.

Blood-sucking leeches suck your blood using two ways: they use a proboscis to puncture your skin, or they use their three jaws and millions of little teeth. They live just about anywhere where there is water. Leeches find you by detecting skin oils, blood, heat, or even the carbon dioxide you breathe out. Leeches do not feed often. This is because they take in a big amount of blood when they feed.

Doctors often used leeches in the past to draw blood. Some barbers used leeches to do surgery as well as cutting hair. When a barber finished surgery, he would take the bloody bandage and wrapped it around a pole to show he did surgery, too. That’s how the white and red swirled barber pole came into use.

Today, maggots and leeches are being used for different reasons. Scientists are studying leech saliva. They believe the substance that stops or prevents blood clots will one day be able to be used on humans. Researchers have also identified several medical compounds which can be developed from leech saliva. The anticoagulant and clot-digesting properties of these substances make them potentially useful as drugs for the treatment of cardiovascular diseases such as heart attacks and strokes. Leeches can be "milked" for their secretions without being harmed, and research is continuing into the possibility of synthetically engineering leech saliva.

But leeches are still being used to suck blood! Doctors are now turning to leeches to help restore blood circulation to grafted tissue and reattached fingers and toes. For example: micro-surgeons in a Boston hospital used leeches to save the ear of a 5 year old boy that had been bitten off by a dog. The leech can remove any congested blood to allow normal circulation to return to the tissues, thus preventing gangrene from starting.

Today, hundreds of thousands of leeches are sold in USA to hospitals, clinics and individuals. The European market is much bigger: millions of leeches are sold every year.

Leech Facts:

• There are 650 known species of leeches.
• The largest leech discovered measured 18 inches.
• About one fifth of leech species live in the sea, where they feed on fish.
• The leech has 32 brains.
• The Hirudo leech lays its babies within a cocoon; whereas the Amazon leech carries its babies on   its stomach - sometimes as many as 300.
• Not all leeches are bloodsuckers. Many are predators which eat earthworms, etc.
• The Amazon leech uses a different method of sucking blood. It inserts a long proboscis into the   victim, as opposed to biting.
• The bite of a leech is painless, due to its own anesthetic.
• The Hirudo leech injects an anti-coagulant serum into the victim to prevent the blood clotting.
• The leech will gorge itself until it has had its fill and then just fall off.
• The leech will gorge itself up to five times its body weight.
• The first leech was used in medicine about 1000 B.C., probably in ancient India.
• In the past, people would stand in the lakes and pools dotted around the country and when the   leeches attached to their legs they would put them in baskets and sell them. Today the Hirudo   leech is an endangered species.
• The original surgeons were barbers and they used leeches to cure anything from headaches to gout!
• The nervous system of the leech is very similar to the human nervous system and is an enormous   benefit to researchers in their quest for the answers to human problems.
• The nearest relatives of leeches are earthworms.
•  Leeches can bite through a hippo's hide.