Americobdella valdiviana
| Americobdella valdiviana | ||||||||||||
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Americobdella valdiviana (head left) |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Americobdellidae | ||||||||||||
| Caballero , 1956 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Americobdella | ||||||||||||
| Caballero , 1956 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Americobdella valdiviana | ||||||||||||
| ( Philippi , 1872) |
Americobdella valdiviana is the name of a species of land-living flukes , which is also the only species of the genus Americobdella and the family Americobdellidae . The large leech, locally known as Liguay in its area of distribution in southern Chile , eats various small animals living in the ground, especially earthworms . It combines features of the throat fluke and jaw fluke and is considered the basal group of the trunkless leeches .
features
Americobdella valdiviana has a large body with an oval cross-section. The leech is usually about 20 cm long and 1.5 cm wide, but lengths of up to 30 cm can also be achieved. Like all belt worms , it is a hermaphrodite . An individual 184 mm long, 15 mm maximum width and 8 mm width at the anus measured 34 mm to the male genital opening with a width of 12 mm there and had a 5 mm long front suction cup and a rear suction cup with a diameter of 6.5 mm. A 206 mm long individual was up to 14 mm wide and 10.5 mm thick at its widest point and had a rear suction cup 5.5 mm in diameter.
Philippi counted around 92 outer ringlets in the individuals he examined. The body is narrow and cylindrical in the front section, gradually increasing in width, in the middle section almost four times as wide and twice as thick as in front and in the rear, longest section again somewhat narrower with almost parallel edges, tapering towards the rear and at the Rounded at the end, almost trimmed at the very end. The back of the leech is convex, the belly flat. The section with the genitals and in front of it is firm and robust due to its thick muscle layer. The front suction cup is formed from the first to the fifth segment.
The leech has a wide mouth with a protruding and rounded front lip, covered with small white papillae, with no ventral median furrow that can be bent over and withdrawn. The rear lip formed by the fused fourth and fifth ring shows wrinkles and folds.
The male genital opening is in the 11th segment (B5 / B6) and the female in the 12th segment (B5 at the furrow B5 / B6). There are 17 pairs of nephridia outlets . The rear suction cup is small and doesn't even get half as wide as the animal's maximum width. Like the ringlets, the back is covered with small white papillae.
While Philippi found no eyes on the leeches, Raul A. Ringuelet counted 6 pairs of rudimentary eyes, namely the first two pairs in the 2nd segment, the third in the 3rd, the fourth in the 4th and the fifth and sixth in the 5th and 6th segment 6th segment. The oral cavity extends to the fourth segment and is delimited by a ring fold. The wide, massive, spindle-shaped pharynx extends from the 4th to the 12th segment and has a strongly muscular wall. It is delimited to the rear by a powerful sphincter . The section of the intestine that follows is a narrow tube with an almost uniform diameter and extends from the 13th to the 19th segment, between which five sphincters sit, each flanked in front by a small pair of blind sacks and behind with a pair of even smaller blind sacks.
The externally not recognizable segments have 5 outer rings per segment in the central body section. The throat is jawless. The testicles are largely arranged like a tree. The unpaired male atrium is hemispherical or pear-shaped and opens outwards together with a bursa copulatrix in the male genital opening. The two ejaculatory ducts open into the prostate chamber of the male atrium on both sides , and at its abdominal end there is a small, muscular penis that can be turned out . The ovaries are tubular like in the roller gels and open outwards via extensive fallopian tubes in the female genital opening located further back.
distribution
Americobdella valdiviana lives at the bottom of moist forests of moderate climate in southern Chile around the city of Valdivia , but was also found in inland waters there.
nutrition
Investigations of the intestinal contents have shown that earthworms are an important food source of Americobdella valdiviana , but in one case water beetles (Hydrophilidae) were also found in the intestine of the leech.
Systematics
Americobdella valdiviana was first described in 1872 by the German-Chilean zoologist Rudolph Amandus Philippi under the name Macrobdella valdiviana . The Mexican zoologist Eduardo Caballero y Caballero established both the monotypical genus Americobdella and the monotypical family Americobdellidae in 1956. The species was named Americobdella valdiviana .
literature
- Rudolph Amandus Philippi (1872): Macrobdella, a new generation of the Hirudinees. Journal for the entire natural sciences (2), new series 6, pp. 439–442.
- Eduardo Caballero y Caballero (1956): Hirudíneos de México. XX. Taxa y nomenclatura de la clase Hirudinea hasta géneros. Anales del Instituto de Biología, Universidad de México 27 (1), pp. 279-302.
- Raul A. Ringuelet (1985): Sinopsis de los Hirudíneos de Chile (Anellida). Boletín de la Sociedad de Biología de Concepción, Chile 56, pp. 163–179, here pp. 171–174. .
- Roy T. Sawyer: Leech Biology and Behavior: Feeding biology, ecology, and systematics. Clarendon Press, Oxford 1986. pp. 536, 681, 790.
- Mark Edward Siddall, Elizabeth Borda (2004): Leech collections from Chile including two new species of Helobdella. American Museum Novitates 3457, pp. 1-18.