Picklescott's leech

Taxobox
name = Picklescott's Leech
status = LR/nt
status_system = IUCN2.3

---

image_width = 220px
image_caption = Picklescott's Leech
regnum = Animalia
phylum = Annelida
classis = Clitellata
ordo = Hirudinea
familia = Hirudidae
genus = "Hirudo"
species = "H. medicinalis"
binomial = "Hirudo interegus"
binomial_authority = Linnaeus, 1758

Picklescott's Leeches, once widespread, are now one of the rarest breeds of medicinal leech.

Morphology

General morphology follows that of most other leeches. Fully mature adults can be up to 22cm in length and are greenish brown with a darker tone on the dorsal side and a lighter ventral side, the dorsal side also has a thin grey stripe. These organisms have two suckers, one at each end, called the anterior and posterior sucker. The posterior is mainly used for leverage while the anterior sucker, consisting of the jaw and teeth, is where the feeding takes place. Picklescott's leeches have three jaws (tripartite) that look like little saws, and on them are about 100 sharp teeth used to incise the host. The incision leaves a mark which is an inverted Y inside of a circle. After piercing the skin and injecting anti-coagulants (Hirudin) and anaesthetics they suck out blood. Large adults can consume up to 15 grams of blood in a single meal. Medicinal leeches are hermaphrodites which reproduce by sexual mating, laying eggs in clutches of up to 50 near (but not under) water, and in shaded, humid places.

Range and ecology

Their range extends over almost the whole of Central America and into South America as far as Colombia and Venezuela. Over-exploitation for medical use in the 19th Century has left only scattered populations and reduction in natural habitat though de-forestation has also contributed to their decline. As a result this species is now considered vulnerable by the IUCN and Picklescott's Leeches are legally protected in several countries in their natural range. They are particularly sparsely distributed in Mexico and Guatemala. There are small transplanted populations in several countries outside their natural range including the USA.

The preferred habitat for this species is muddy freshwater pools and ditches with plentiful tree cover in hot climates.

In modern medicine

Medicinal leeches are now making a comeback. They provide an effective means to reduce blood coagulation, relieve venous pressure from pooling blood, especially after plastic surgery, and stimulate circulation in reattachment operations for organs with critical blood flow, such as eye lids, fingers, and ears.

Because of the minuscule amounts of hirudin present in leeches, it is impractical to harvest the substance for widespread medical use. Hirudin (and related substances) are synthesised using recombinant techniques.

They are also being used in relation to the treatment of various Varicose conditions.

http://www.medicalleech.info/varicose-veins.htm

Devices called "mechanical leeches" have been developed which dispense herapin and perform the same function as medicinal leeches, but they are not yet commercially available. [Salleh, Anna. [http://www.abc.net.au/science/news/health/HealthRepublish_439856.htm A mechanical medicinal leech?] "ABC Science Online." 2001-12-14. Retrieved on 2007-07-29.] [Crystal, Charlotte. [http://www.virginia.edu/topnews/releases2000/cottlerleech-dec-14-2000.html Biomedical Engineering Student Invents Mechanical Leech] "University of Virginia News". 2000-12-14. Retrieved on 2007-07-29.] [Fox, Maggie. [http://www.otoweb.org/news_folder/mech_leech/mech_leech_A.htm ENT Research Group Recognized for Mechanical Leech Project] "Otoweb". University of Wisconsin, Madison, Division of Otolaryngology. Retrieved on 2007-07-29.]

References

* [http://www.Hirudolab.com Hirudolab, Clinical information including contra-indication, and worldwide supplier to hospitals and research laboratories.]
* [http://www.leechesturkey.com Medicinal Leech, Turkey, Supplier of Medicinal Leeches]
* [http://www.leeches.biz/safety-adverse-effects.htm Information about Safety and Adverse Effects of Leech Therapy]
* [http://www.disgustingly-healthy.com Documentary about alternative medicine with leeches and maggots]
* [http://www.pbs.org/wnet/redgold/basics/bloodlettinghistory.html Document concerning the history of Bloodletting]