Orobdella

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Orobdella
Orobdella masaakikuroiwai

Orobdella masaakikuroiwai

Systematics
Subclass : Leeches (Hirudinea)
Subclass : Bristle flukes (Arhynchobdellida)
Order : Trunkless leeches (Arhynchobdellida)
Subordination : Schlundegel (Erpobdelliformes)
Family : Orobdellidae
Genre : Orobdella
Scientific name of the  family
Orobdellidae
Nakano , Ramlah & Hikida , 2012
Scientific name of the  genus
Orobdella
Oka , 1895
Orobdella masaakikuroiwai under a stone

Orobdella is the name of a genus of predatory flukes thatlive on land, the only genus of the monogeneric family Orobdellidae in the order of the throat leeches thatare commonin Japan and Taiwan and particularlyeat earthworms .

features

The leeches of the genus Orobdella have a cylindrical body shape, but are more or less flattened towards the rear, with the side edges running almost parallel over a large part of the body and this only tapers slightly at the two ends. The number of outer ringlets per segment in the middle section of the body differs depending on the species, but is constant within each species and is either 4, 6 or 8. The surface of the ringlets is smooth and without any protrusions, the furrows between the rings are clear, but not deep. The mouth opening on the stomach side at the front end of the animal takes up the space of 4 to 6 ringlets, while the following two ringlets on the stomach side form the rear lip of the mouth. The leeches have a pair of eyes on the rear edge of the second ring. A pair of small pigment spots act as rudimentary eyes on the 4th ringlet.

The male sexual opening of the hermaphroditic animals sits on the belly side on the 27th ring, the female on the 32nd ring, so that there are 4 ringlets between the two openings. The clitellum occupies 12 ringlets, starting on the 22nd and ending on the 33rd ring. On the 13th or 14th segment there may be a gastropore on the abdomen - an opening that opens outwards from the intestinal canal.

The rear suction cup (acetabulum) is egg-shaped and measures just under half the width of the leech. The anus sits on the rear surface of the suction cup about a ring width behind the rear edge of the last ring.

Most flukes of the genus Orobdella reach lengths of about 10 cm. The Orobdella octonaria native to Honshu , which has 8 ringlets per segment in the middle of the body and a gastropore on the belly, is the largest species and can grow to over 20 cm long. Small species with maximum lengths of less than 4 cm - both with four stripes per segment - on are Hokkaido living Orobdella koikei and living in the central Honshu Orobdella masaakikuroiwai . The adult specimens of the Honshu species Orobdella whitmani preserved by Asajiro Oka are about 7 to 8 cm long, 5 to 6 mm wide and 4 to 4.5 mm thick.

Distribution, habitat and way of life

The leeches of the genus Orobdella are common in the mountains of Japan and Taiwan . They are rural dwellers who prefer to live on the forest floors of mountain forests. The leeches predatory feed on other annelid worms , especially earthworms . The prey is swallowed whole using the muscular pharynx.

Systematics

In 1895, the Japanese zoologist Asajiro Oka described the genus Orobdella at the same time as three species belonging to it and found in Japan. The name chosen by him "mountain leech" ( ancient Greek ὄρος óros "mountain", Greek βδέλλα bdélla " leech ") indicates the Japanese mountains as the habitat of these leeches, which were initially placed in the Erpobdellidae family . While the Japanese Takafumi Nakano beginning this Egelgattung family Gastrostomobdellidae zuordnete he introduced in 2012 together with Ramlah bt Zainudin and Tsutomu Hikida the mono generic family Orobdellidae, which he founded, among other things with the different anatomy of the gastro pores in Orobdella have a tubular shape.

The genus Orobdella includes the following species :

literature