Leeches - Subclass: Hirudinea
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Australia is home to about 100 species of leeches with most of these found between Brisbane and Tasmania. The Northern Rivers would probably host about 18 species but this estimate is likely to be conservative as leeches occur in a range of habitats most, if not all of which do occur in the region. Not all leeches are parasites, most are actually predatory and feed on small invertebrates such as insects, snails,and slugs or worms. Those that are parasitic feed on the blood of other animals, cold-blooded or warm. They will not shy away from latching on to humans either, a trait that is proving to be quite fortunate and is used more and more (again) for the treatment of certain medical conditions. As well as that they are used also to expedite the healing processes after surgery
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All leeches have a sucker at either end of the body. Predatory leeches have protruding from the 'mouth' sucker, a proboscis, a tongue-like structure to pierce and suck up the internal tissues of their prey. The front sucker of parasitic leeches usually has jaws - often three - with sharp teeth that are used to make a Y-shaped cut into the skin of the host animal. The leeches' saliva contains a number of proteins including, blood thinners, anti-coagulants and others to ensure ongoing bloodflow during the feeding session after which the leech simply allows it self to fall off the host. The leech can easily consume upto five times its' own weight in blood and may not feed again for weeks or even months.
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Fossils of leeches are only rarely found but the oldest discovered sofar is about 266 My old from the Permian period (299 - 252 Mya). There could be slightly older types but evidence for these examples is still being debated. Since their appearance in the fossil record, leeches haven't changed much and modern leeches all look remarkably similar. which, of course, makes identification difficult. On top of that, immature leeches differ only from the adults in being smaller.
Whereas leeches lay eggs and reproduce sexually, they are hermaphrodites, having both male and female sexual organs. Unlike earthworms which develop a permanent clitellum at maturity, leeches only have this feature during the breeding season. its' use and purpose remains the same, though. |
Order: Arhynchobdellida
Unplaced Family: Erpobdellidae
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Genus ?
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Suborder: Hirudiniformes
Family: Haemadipsidae
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Chtonobdella sp.
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Haemadipsa sp.
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Family: Haemopidae
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Haemopis sp.
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Family: Hirudinidae
Subfamily: Ornithobdellinae
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Ornithobdella sp.
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Subfamily: Richardsonianinae
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Richardsonianus sp.
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Order: Rhynchobdellida
Family: Glossiphoniidae
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Alboglossiphonia sp.
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Helobdella sp.
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Placobdelloides sp. (possible occurrence)
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Family: Piscocolidae
Subfamily: Piscocolinae
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Trachelobdella sp. (possible occurrence)
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Subfamily: Pontobdellinae
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Pontobdella sp. (possible occurrence)
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Stibarobdella sp.
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Taxonomy:
Phylum: Annelida (Segmented Worms)
> Class: Clitellata (Leeches)
> Subclass: Hirudinea (Leeches)
> Infraclass: Euhirudinea (True Leeches)
> Order: Arhynchobdellida (Proboscisless Leeches)
> Family: Erpobdellidae ^
> Suborder: Hirudiniformes
> Family: Haemadipsidae (Jawed Land leeches)
> Genus: Chtonobdella (Jawed Leeches)
> Genus: Haemadipsa (Jawed Land Leeches)
> Family: Haemopidae
> Genus: Haemopis
> Family: Hirudinidae
> Subfamily: Ornithobdellinae
> Genus: Ornithobdella
> Subfamily: Richardsonianinae
> Genus: Richardsonianus
> Order: Rhynchobdellida (Jawless Leeches)
> Family: Glossiphoniidae
> Genus: Alboglossiphonia
> Genus: Helobdella
> Genus: Placobdelloides ^
> Family: Piscicolidae (Fish Leeches)
> Subfamily: Piscicolinae
> Genus: Trachelobdella ^
> Subfamily: Pontobdellinae
> Genus: Pontobdella ^ (Shark Leeches)
> Genus: Stibarobdella
^ = possibly
The taxonomic arrangement above is as per iNaturalist which differs from that in the Catalogue of Life in that in the latter the Hirundinea are no longer regarded as a subclass but instead have been downgraded to family level. (Dec 2023)
References and links:
> Prevec, R., Nel, A., Day, M.O., Muir, R.A., Matiwane, A., Kirkaldy, A.P., Moyo, S., Staniczek, A., Cariglino, B., Maseko, Z., Kom, N., Rubidge, B.S., Garrouste, R., Holland, A. and Barber-James, H.M., (2022). 'South African Lagerstätte reveals middle Permian Gondwanan lakeshore ecosystem in exquisite detail.' Commun Biol. 2022 Oct 30;5(1):1154.
doi: 10.1038/s42003-022-04132-y
https://www.britannica.com/science/Permian-Period
https://www.catalogueoflife.org/
https://en.wikipedia.org/wiki/Hermaphrodite
https://en.wikipedia.org/wiki/Hirudo_medicinalis
https://www.laphamsquarterly.org/roundtable/arsenic-and-old-leeches
https://www.maine.gov/dep/water/monitoring/biomonitoring/sampling/bugs/leeches.html
https://www.uhcw.nhs.uk/download/clientfiles/files/leech%20therapy(1).pdf
http://www.wettropics.gov.au/site/user-assets/docs/leeches.pdf
> Prevec, R., Nel, A., Day, M.O., Muir, R.A., Matiwane, A., Kirkaldy, A.P., Moyo, S., Staniczek, A., Cariglino, B., Maseko, Z., Kom, N., Rubidge, B.S., Garrouste, R., Holland, A. and Barber-James, H.M., (2022). 'South African Lagerstätte reveals middle Permian Gondwanan lakeshore ecosystem in exquisite detail.' Commun Biol. 2022 Oct 30;5(1):1154.
doi: 10.1038/s42003-022-04132-y
https://www.britannica.com/science/Permian-Period
https://www.catalogueoflife.org/
https://en.wikipedia.org/wiki/Hermaphrodite
https://en.wikipedia.org/wiki/Hirudo_medicinalis
https://www.laphamsquarterly.org/roundtable/arsenic-and-old-leeches
https://www.maine.gov/dep/water/monitoring/biomonitoring/sampling/bugs/leeches.html
https://www.uhcw.nhs.uk/download/clientfiles/files/leech%20therapy(1).pdf
http://www.wettropics.gov.au/site/user-assets/docs/leeches.pdf
Photographic contributions: