Well it’s become quite busy as spring has sprung, the clocks creep forward and the sun begins to shine. Last week we had something to scream about when we focused on the Pharaoh Cicada, an insect that’s so elusive it only appears every seventeen years. This week we have a tyrannical dinosaurian issue, hope you guys enjoy.
Issue #167 – T.rex
Kingdom – Animalia
Phylum – Annelida…
Wait!! Not more worms, yep April Fools!! Let’s start this again.
Issue #167 - T.rex Leech
Kingdom – Animalia
Phylum – Annelida
Class – Clitelllata
Order – Hirudinea
Family – Praobdellidae
Genus – Tyrannobdella
Species – rex
Related Species -Tyrannobdella rex is currently the only member of its genus (1)
Range - So far Tyrannobdella rex has only been found in villages along the banks of the Peruvian Amazon
Tyrant Leech King
Tyrannobdella rex (whose name translates to Tyrant Leech King) is a small leech which has a girth of a centimetre and a length of about 3cm when fully grown. Like the majority of leeches, T.rex is largely aquatic, and navigates its watery home using chemical cues as well as a ring of eyes on the first (of 32 segments). Incidentally each segment of T.rex’s body contains its own brain, with the first four segments classed as the head, the next 21 classed as the mid-body which contains the stomach and reproductive organs, with the last seven segments fused together to form the leeches tail sucker and posterior brain (2).
Like several other species of leech Tyrannobdella feeds on blood fresh from a mammalian host. Unlike most species, T.rex prefers to feed internally on its host, either from inside the nose or the reproductive system of its victim, usually chewing through to the blood vessels with the eight large teeth (up to 0.13mm in length) that ring its jaw (another oddity since most leeches have three jaws). While most leeches are content to drop off their host when they’ve had their fill, T.rex will remain feeding for up to three months before vacating its host. At current the natural host of T.rex is unknown, since it has only been recorded from the noses of humans it infiltrated when they were swimming or bathing in the rivers T.rex lives in (3).
Like most leeches, Tyrannobdella rex is a hermaphrodite with each individual leech containing both male and female reproductive organs. The pair of leeches will line up against each other and shoot its mate with an injection of sperm which then travels up to the female reproductive organs of the female. Once fertilized the leeches will lay their eggs in a capsule (much like those laid by earthworms) on a plant, with the juvenile leeches emerging sometime later as miniature versions of their parents.
Five Creepy Leeches
The Giant Amazon Leech (Haementeria ghilianii) is the largest of the blood sucking leeches, with fully grown specimens as long as 45cm when fully grown accurately recorded.
Not all leeches are parasites, a large number are scavengers, and some are predators. The Kinabalu Giant Red Leech (Mimobdella buttikoferi) which can grow up to half a meter in length, is a good example of this, and feeds solely on earthworms and smaller leeches.
Not all leeches are restricted to watery habitats, a fair number of tropical species can be found in terrestrial habitats, particularly those that have a high humidity that prevent desiccation of the leech. Among these species the Tiger Leech (Haemadipsa picta), also known as the Stinging Land Leech, is the most well-known due to its relative abundance and unusually painful bite.
In addition to terrestrial leeches, there also marine leeches that live predominantly in salt water. Among these species is the Antarctic Leech (Trulliobdella captis) which feeds on fish, and is the only species that lives around the cold waters of the Falklands and the Sandwich Isles (4).
No conversation about leeches is complete without mentioning the European Medicinal Leech (Hirudo medicinallis), a species that was so readily harvested for medical practices that it is now protected by the Convention on International Trade in Endangered Species (CITES). This species is sought after for medical practices due to the anticoagulant properties of the saliva, and is still used in ‘leech therapy’ to this very day.
2 - Brian Payton (1981). Kenneth Muller; John Nicholls; Gunther Stent, eds. Neurobiology of the Leech. New York: Cold Spring Harbor Laboratory. pp. 35–50
3 - https://phys.org/news/2010-04-rex-leech-affinity-noses.html
4 - http://bionames.org/bionames-archive/issn/0018-0130/50/138.pdf
5 - Teiji Sota; Satoshi Yamamoto; John R. Cooley; Kathy B. R. Hill; Chris Simon; Jin Yoshimura (2013). "Independent divergence of 13- and 17-y life cycles among three periodical cicada lineages". Proceedings of the National Academy of Sciences of the United States of America. 110 (2): 6919–6924
1 - https://i.kinja-img.com/gawker-media/image/upload/s---oL1N5XV--/c_scale,f_auto,fl_progressive,q_80,w_800/813266302148042132.jpg
2 - https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2011/anewlydiscov.jpg
3 - https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/Tyrannobdella_rex_teeth.png/220px-Tyrannobdella_rex_teeth.png
4 - http://i.telegraph.co.uk/multimedia/archive/03052/Leech_3052497k.jpg
5 - http://www.hirudohorti.com/wp-content/uploads/2015/07/Medicinal-leeches.jpg
Well that’s April Fools over for another year, and to any bdellaphobics I offer my most sincere apologies to any distress I caused you. Next week we follow an unusual mammal as it takes to the water, but until then make sure to critic, comment and suggest future issues as well as making sure you check past issues in Impurest’s Bestiary