Haementeria ghilianii
| Haementeria ghilianii | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Clade: | Sedentaria |
| Class: | Clitellata |
| Subclass: | Hirudinea |
| Order: | Rhynchobdellida |
| Family: | Glossiphoniidae |
| Genus: | Haementeria |
| Species: | H. ghilianii
|
| Binomial name | |
| Haementeria ghilianii de Filippi, 1849
| |
Haementeria ghilianii, commonly known as the Amazon giant leech, is one of the world's largest species of leeches.
Taxonomy and discovery
[edit]Haementeria ghilianii is a species of leech in the Glossiphoniidae family, comprising freshwater proboscis-bearing leeches. Colloquially, they are known as the Amazon giant leech. The species was declared extinct in 1893 after no wild specimen could be found.[1]
Rediscovery and colonization
[edit]In the 1970s, Dr. Roy Sawyer discovered two adult specimens in a pond located in French Guiana. One of these leeches, dubbed Grandma Moses, founded a successful breeding colony at UC Berkeley. This specimen produced 750 offspring.[1] Following Grandma Moses' death, the specimen was placed in the Smithsonian's National Invertebrate Collection.[2]
Description
[edit]Haementeria ghilianii is a jawless, blood sucking leech. It can grow to 450 mm (17.7 in) in length and 100 mm (3.9 in) in width.[1] This makes it the largest freshwater leech known.[2] As adults, these leeches are a uniform greyish-brown color. Juveniles do not have a uniform color, but rather, a noncontinuous greyish-brown stripe and patches of color. The leeches form a "cobra hood" like shape that is widest in the center but tapers off on both ends.[1][2] The wider end is where the proboscis is located, while the head is at the narrow end; H. ghilianii is made up 34 segments, each with its own ganglia.[3]
Life cycle
[edit]This species is hermaphroditic; the male reproductive system is 3 g (0.0066 lb) to 5 g (0.011 lb) while the female reproductive system is 10 g (0.022 lb).[2][1] Growth is irregular, as the leech's body weight increases by 3 to 6 fold times per feeding. Fecundity is based upon the weight of the leech during oviposition; egg clutches range from 60 to 500 eggs.[4]
Behavior and ecology
[edit]When stressed, leeches will produce mucus to evade predators.[3]
Feeding
[edit]Unlike jawed leeches who use rows of teeth to puncture skin, Haementeria ghilianii uses a 10 centimetres (3.9 in) hypodermic needle style proboscis to feed. Bites are kept open by the fibrinogenolytic (breaks up fibrinogen) enzyme hementin, which is secreted from the proboscis' lumen; secretion is neurologically controlled. Hementin dissolves clots within the proboscis by breaking up the fibrinogen links between individual platelets. Once attached to a host, they release anticoagulants to prevent clotting. Then, the leeches extract blood at a rate of up to 0.14 ml/min, consuming 15 ml of blood total.[1][5] Blood is moved into the digestive system through a series of undulation movements, and leeches can go months without feeding.[3][5] Observed host species include humans, rabbits, and cows.[1][5] Claims from 1899 state that leeches could aggregate to the point of killing birds and cattle.[3]
Distribution
[edit]Haementeria ghilianii is endemic to the northern portions of the Amazon river, ranging from Venezuela and the Guianas.[1]
References
[edit]- ^ a b c d e f g h Steven Ryan (1 May 2015). "Amazon Giant Leech (Haementeria ghilianii)". University of Northern British Columbia blogs. Archived from the original on 31 August 2018. Retrieved 14 October 2018. Article with photograph.
- ^ a b c d Magazine, Smithsonian; Gambino, Megan. "The List: 5 Weirdest Worms at the Smithsonian". Smithsonian Magazine. Retrieved 2024-01-24.
- ^ a b c d Taiwo, Victor (2022). "What Is the Largest Leech Ever Discovered?". A-Z animals.
- ^ Sawyer, Roy T.; Lepont, Francois; Stuart, Duncan K.; Kramer, Andrew P. (1981). "Growth and Reproduction of the Giant Glossiphoniid Leech Haementeria ghilianii". The Biological Bulletin. 160 (2): 322–331. doi:10.2307/1540892. ISSN 0006-3185. JSTOR 1540892.
- ^ a b c Sawyer, R. T.; Jones, C. P.; Munro, R. (1991). "The biological function of hementin in the proboscis of the leech Haementeria ghilianii". Blood Coagulation & Fibrinolysis. 2 (1): 153–159. doi:10.1097/00001721-199102000-00023. ISSN 0957-5235. PMID 1772983.