| Placobdella costata | |
|---|---|
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| Placobdella costata in Jeti, Estonia | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Clade: | Sedentaria |
| Class: | Clitellata |
| Subclass: | Hirudinea |
| Order: | Rhynchobdellida |
| Family: | Glossiphoniidae |
| Genus: | Placobdella |
| Species: | P. costata |
| Binomial name | |
| Placobdella costata (Müller, 1846) | |
| Synonyms | |
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Placobdella costata is a species of Glossiphoniid leech found in European waters.
Placobdella costata was described as Clespine costata by Friedrich Müller, in 1846, and it then underwent several name changes and reclassifications. Glossiphonia catenigera, a different name for the same organism, was described in the same year by Alfred Moquin-Tandon and is treated as a junior synonym. [1] [2] As Raphaël Blanchard noted in an 1893 paper, the species "was described at almost the same time by Moquin-Tandon and by Fr. Müller." [3] Nonetheless, Blanchard took Müller's name as the basionym for the species which was then called Placobdella catenigera, and listed Moquin-Tandon's species as a synonym, along with a couple other names, [1] a classification which has endured. [4]
Genetic analyses have placed Placobdella costata as sister to a clade comprising P. phalera and P. transfuscens . This clade of three species is in turn sister to a clade which includes Placobdella parasitica , [5] a common North American species. [6]
| Phylogeny of P. costata and related species | |||||||||||||||||||||||||||||||||||||||||||||||||||
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| After Siddall et. al., 2006 |
Placobdella costata is found in much of central Europe, and is "widely distributed... in the European Mediterranean area", as well as being found from Morocco to Iran and Caucasia, [7] the Scandinavian and Arabian peninsulas. In Great Britain, [4] where it was first described in 1979, [8] it is very rare. [9] In the Iberian peninsula, it is known from the northern and central regions, as well as Andalusia. [7]
Placobdella costata is a large, elliptical, flattened leech, [10] with somewhat variable colour. At rest, the adults are between 2 and 7 centimetres (0.79 and 2.76 in) long, and between 0.6 and 2.5 centimetres (0.24 and 0.98 in) wide. [11] In colour the leeches can be greenish-brown, [10] dark brown, blue-green, or, more often, yellowish-brown. They have an interrupted dark brown band down the middle of their backs. [11]
Placobdella costata is somewhat unusual among Glossiphoniid leeches in that its mouth is located towards the front of its anterior sucker, while in many other species the mouth is in the centre of the sucker. [12] This forwards mouth is shared by other species which parasitize mammals and reptiles, including Haementeria ghilianii . [13]
Leeches have exhibit a variety of eye types, numbers, and arrangements, and are therefore "taxonomically invaluable". [14] Within the family Glossiphoniidae alone there is considerable diversity. Placobdella costata at first appears to have two very close, often touching, eyes on its third segment, but more detailed observation with the use of histological techniques has shown that the leeches additionally have a pair of small, "rudimentary" eyes, anterior to and below its primary pair. [15]