---
title: "What the sources say about the European Medicinal Leech | AnimalTracks.wiki"
description: "42 claims from the European Medicinal Leech profile, each beside the words of the source that backs it."
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# What the sources say about the European Medicinal Leech (*Hirudo medicinalis*)

> 42 claims from the European Medicinal Leech profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [European Medicinal Leech](https://animaltracks.wiki/animals/european-medicinal-leech/)

## Utevsky, Zagmajster & Trontelj (2014). Hirudo medicinalis. The IUCN Red List of Threatened Species 2014: e.T10190A21415816.

https://doi.org/10.2305/iucn.uk.2014-1.rlts.t10190a21415816.en

| The page says | The source says |
| :--- | :--- |
| Near Threatened | IUCN Red List category: Near Threatened (NT). (note: stats.conservationStatus; read through GBIF's copy of the Red List) |
| The IUCN Red List rates it Near Threatened | IUCN Red List category: Near Threatened (NT). (note: faq 4; years dropped: the 2013 assessment year was a hand note, and Crossref's issued date (2013-12-19) does not match the 2014 edition label) |
| The IUCN rates it Near Threatened. | IUCN Red List category: Near Threatened (NT). (note: category read through GBIF's copy of the Red List) |

## Medicinal Leech. Buglife.

https://buglife.org.uk/bugs/bug-directory/medicinal-leech

| The page says | The source says |
| :--- | :--- |
| overharvested for medicine | the IUCN categorising it as globally Near Threatened due primarily to the overharvesting of leeches in the past for medical use (note: tagline) |
| Typically blood from mammals such as deer, sheep and cattle | Medicinal Leeches typically feed on blood from mammals such as deer, sheep and cattle which enter the water to drink. (note: stats.diet) |
| young leeches take the young of frogs, toads and newts | Juvenile leeches will feed upon the young of frogs, toads and newts. (note: stats.diet and body) |
| Buglife gives its length as up to 20 cm | Up to 20cm in length |
| largest native leech in the UK | The Medicinal Leech ( Hirudo medicinalis ) is the largest, native leech found in the UK. (note: body) |
| five pairs of eyes | The Medicinal Leech has five pairs of eyes. |
| An adult may not feed again for 12 to 18 months. | Once fully fed, an adult leech may not feed again for 12 to 18 months |
| it takes at least two years to reach breeding age, and maybe four | They take at least two years to reach breeding maturity, but this may take as long as four years. |
| usually small pools with muddy bottoms fringed with reeds | usually in small pools with muddy bottoms and fringed with reeds |
| Medicinal leeches were once used heavily in medicine, and many wild populations were collected to supply bloodletting. | Medicinal Leeches were used extensively in medicine historically and many wild populations were exploited to supply leeches for bloodletting. |
| the species is now rare across Europe and extinct in much of its former range, mainly due to that overharvesting | it is now rare throughout its range in Europe and extinct in much of its former range, with the IUCN categorising it as globally Near Threatened due primarily to the overharvesting of leeches |
| In the UK, Buglife counts around 20 isolated populations. | There are around 20 isolated populations from Kent, Hampshire and Cumbria in England |
| health care professionals still use a related species, the Mediterranean medicinal leech (Hirudo verbana) | A related species, the Mediterranean Medicinal Leech ( Hirudo verbana ) is still used by health care professionals. |
| Adults typically feed on mammals such as deer, sheep and cattle that come into the water for a drink. | Medicinal Leeches typically feed on blood from mammals such as deer, sheep and cattle which enter the water to drink. |
| Up to 20 cm long, according to Buglife | Up to 20cm in length (note: faq 1) |
| no native UK leech is bigger | The Medicinal Leech ( Hirudo medicinalis ) is the largest, native leech found in the UK. (note: faq 1) |
| Young leeches feed on the young of frogs, toads and newts. | Juvenile leeches will feed upon the young of frogs, toads and newts. |

## European medicinal leech. New Forest Wildlife Park.

https://newforestwildlifepark.co.uk/what-to-see-and-do/animals/european-medicinal-leech/

| The page says | The source says |
| :--- | :--- |
| A three-jawed pond blood-drinker | they use three powerful jaws lined with around 100 tiny teeth to latch onto a host (note: tagline, jaws) |
| one blood meal that can last it 12 to 18 months | a medicinal leech may not need to feed again for 12–18 months (note: tagline, superpower) |
| Ponds, lakes and small pools across much of Europe and into Asia | Habitat - Ponds, lakes and small pools. (note: stats.habitat) |
| across much of Europe and into Asia | Distribution - Across much of Europe and into Asia. (note: stats.habitat and body range) |
| three jaws lined with around 100 tiny teeth | they use three powerful jaws lined with around 100 tiny teeth to latch onto a host |
| it releases hirudin, a natural anticoagulant, meaning a chemical that stops blood clotting | releasing a natural anticoagulant called hirudin that prevents the blood from clotting |
| Its body has 34 segments | These fascinating animals have 34 body segments and five pairs of eyes (note: ADW says 33 or 34; the zoo's 34 is used) |
| up to 20 years in captivity | Up to 20 years in captivity. (note: body and faq 2) |
| Three Jaws and a Chemical Cocktail | they use three powerful jaws lined with around 100 tiny teeth to latch onto a host (note: heading) |
| can go 12 to 18 months between meals | a medicinal leech may not need to feed again for 12–18 months (note: tagline; 'can go' for 'may not need to feed again') |

## Hirudo medicinalis. Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Hirudo_medicinalis/

| The page says | The source says |
| :--- | :--- |
| the bite leaves a star-shaped scar with three arms | leaves a tripartite star-shaped scar on the host |
| Moving shadows overhead often mean a mammal is near, and the leech reacts to them, especially when it is hungry. | Especially when "hungry" H. medicinalis will respond to moving shadows, which often indiciate a source of mammalian food. (note: ADW 2002; quote has the page's own typo 'indiciate') |
| Shadow reflex | The leech is able to detect the movement of shadows above. (note: blockquote lead-in; ADW's own heading 'Shadow reflex') |
| reacts to moving shadows overhead, which often mean a mammal is near | Especially when "hungry" H. medicinalis will respond to moving shadows, which often indiciate a source of mammalian food. (note: vibe.reason; same quote as the body sentence "Moving shadows overhead often mean a mammal is near, and the leech reacts to the") |

## Lent et al. (1988). Ingestive Behaviour and Physiology of the Medicinal Leech. Journal of Experimental Biology.

https://doi.org/10.1242/jeb.137.1.513

| The page says | The source says |
| :--- | :--- |
| A 1988 lab study of leeches named as *Hirudo medicinalis* | Ingestion lasts 25 min in Hirudo medicinalis (note: year from the reference; 'named as' because many lab leeches sold as H. medicinalis are H. verbana) |
| 1-g leeches took a meal of 8.4 g | 8.4 g for 1-g leeches and 9.7 g for 2-g leeches |
| about 8 times their own body mass | from 8.15 times body mass for 1-g to 4.80 times for 2-g leeches (note: 8.15 rounded to 'about 8') |
| in around 25 minutes | Ingestion lasts 25 min in Hirudo medicinalis |

## Harvey et al. (1986). Cloning and expression of a cDNA coding for the anticoagulant hirudin from the bloodsucking leech, Hirudo medicinalis. Proceedings of the National Academy of Sciences.

https://doi.org/10.1073/pnas.83.4.1084

| The page says | The source says |
| :--- | :--- |
| Anticoagulant saliva | hirudin, a potent thrombin inhibitor that is secreted by the salivary glands of the medicinal leech, Hirudo medicinalis (note: stats.superpower; the saliva link is Harvey's, not the zoo's) |
| A 1986 study calls hirudin a potent thrombin inhibitor made in the leech's salivary glands. | hirudin, a potent thrombin inhibitor that is secreted by the salivary glands of the medicinal leech, Hirudo medicinalis |

## Mumcuoglu (2014). Recommendations for the Use of Leeches in Reconstructive Plastic Surgery. Evidence-Based Complementary and Alternative Medicine.

https://doi.org/10.1155/2014/205929

| The page says | The source says |
| :--- | :--- |
| A 2014 review reports that the FDA approved leeches in July 2004 as a medical device for plastic and reconstructive surgery | In July 2004, the FDA approved leeches as a medical device in the field of plastic and reconstructive surgery. (note: review published 2014 (Evid Based Complement Alternat Med)) |
| Leeches still have a place in the clinic. | the majority of these units uses leeches postoperatively (note: UK and Ireland plastic surgery units, per the 2014 review) |