North American leech
| North American leech | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Macrobdella decora | ||||||||||||
| ( Say , 1824) |
The North American leech ( Macrobdella decora ), also known as the American medical leech , is a type of leech from the Macrobdellidae family in the order of the jaw rule that lives in freshwater and sucks the blood of various vertebrates as an ectoparasite . It is common in North America .
features
The body of Macrobdella decora is laterally flattened and reaches a length of about 11 to 15 cm. The leech has a green back with about 20 red or orange spots along the center line and black spots on the sides. The ventral side is colored red or orange and covered with individual black spots. On each of the three jaws there are 50 to 65 small sharp teeth in a row (monostichodont). The leech has two pairs of copulation glands, the openings of which are visible on the belly side. Like all leeches he is a hermaphrodite ; there are five to five and a half outer ringlets between the male and female genitals.
distribution and habitat
The North American leech is common in stagnant and slow-moving inland waters in the northern United States and Canada . It is more common in pools or swamps and ditches with thick vegetation than in rivers and large open lakes.
nutrition
Macrobdella decora sucks blood especially from amphibians and turtles , but when the opportunity arises, the leech also sucks human blood . In some inland waters of Canada and the USA, such as Palisades Interstate Park , New York , the leech falls on people in such large numbers that they are avoided or closed as bathing waters. He also eats amphibians eggs, such as the spawning of the North American bullfrog , and sludge tube worms , earthworms , insect larvae , leeches, snails and other small animals. Its forays are associated with up to 80% of the breeding losses of the American toad Bufo americanus .
Life cycle
The North American leech needs a large meal in the spring to be able to reproduce. As a hermaphrodite , two leeches mate with each other with their penises . With the help of the clitellum, after mating, both partners secrete a straw-colored elliptical cocoon made of a spongy chitinous material in which they lay around 8 or 16 eggs, depending on the conditions. In New York , cocoons are laid in the mud under wood or rocks at the edge of the water in June or July, and young ready-made leeches hatch in July and August. In the laboratory, the cocoons are laid one to two months after the spring meal, and after 28 to 30 days, an average of 16 young animals with a length of 20 to 22 mm hatch. Sexual maturity is reached at around 2 years of age.
Systematics
Macrobdella decora was first described in 1824 by the American zoologist Thomas Say under the name Hirudo decora . His compatriot Addison Emery Verrill introduced the genus Macrobdella ("long leech", ancient Greek μακρός makrós , "long" and βδέλλα bdélla , "leech") in 1872 and gave the species the name Macrobdella decora . Not to be confused with this is the homonymous genus Macrobdella , which was also established by Rudolph Amandus Philippi in 1872 and used for the Chilean leech species known today as Americobdella valdiviana .
literature
- James H. Thorp, Alan P. Covich: Ecology and Classification of North American Freshwater Invertebrates. Academic Press, London 2010. p. 433.
- James H. Thorp, D. Christopher Rogers: Thorp and Covich's Freshwater Invertebrates: Keys to Nearctic Fauna. Elsevier, Amsterdam 2015. p. 257.
- Roy T. Sawyer: North American Freshwater Leeches, Exclusive of the Piscicolidae, with a Key to All Species. Illinois Biological Monographs 46, University of Illinois Press, Urbana-Champaign / Chicago / London 1972. pp. 66-69 .
- Addison E. Verrill (1872): Description of North American fresh-water leeches. Brief contributions to zoölogy from the Museum of Yale College. No. XVII. The American Journal of Science and Arts, Series 3, No. 3 (14), pp. 126-139.