Ocnerodrilidae

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Ocnerodrilidae
Systematics
Over trunk : Lophotrochozoa (Lophotrochozoa)
Trunk : Annelids (Annelida)
Class : Belt worms (Clitellata)
Subclass : Little bristle (Oligochaeta)
Order : Earthworms in the broader sense (Crassiclitellata)
Family : Ocnerodrilidae
Scientific name
Ocnerodrilidae
Beddard , 1891

Ocnerodrilidae (from Greek οκνηρός "lazy, lazy" and δρίλος "earthworm") is the name of a family of little bristles in the order of the Crassiclitellata (earthworms in the broader sense), whose several hundred species are distributed in South America , Central America , North America , Africa and South Asia are and mostly live semi-aquatic .

features

The Ocnerodrilidae have a cylindrical body with only rarely dorsal pores. You have 1 or 2 gizzards in the esophagus but none in the midgut. Calcified glands of the foregut are in the 9th segment, and in the Ocnerodrilinae also in the 10th segment. Within the closed blood vessel system , a supra-oesophageal blood vessel also runs in the front section of the animal in addition to the dorsal vessel above the esophagus. The large nephridia are well developed.

The clitellum is ring-shaped or saddle-shaped and takes up to 7 segments between the 12th and the 18th segment, in Nematogenia, exceptionally, 13 segments up to the 26th segment. There are no pubertal tuberosities, but genital papillae or porophores are generally present.

Like all girdle worms , the Ocnerodrilidae are hermaphrodites with two pairs of testes in the 10th and 11th segment and behind them a pair of ovaries in the 13th segment, which release their eggs into the open air via an unpaired or a pair of female sexual openings ventrally on the 14th segment. The sperm conductors, on the other hand, cross several segments, including the ovary-bearing one, and the pair of male genital orifices is located behind the female abdominal side on the 17th or 18th segment, rarely on the 19th or 20th segment within the clitellum or on its rear edge. The 1 to 3 pairs of prostates are tubular with a central channel and open outwards into 1 to 2 pairs of prostate pores between the 16th and 21st segment. The receptacula seminis seldom have blind sacs and open out in front of the testicles.

Distribution, habitat and way of life

The representatives of the large subfamily Ocnerodrilinae are distributed in western North America , in Central America including numerous islands of the Caribbean and in tropical South America , in all of Africa south of the Sahara and in the valley of the Nile as well as in Madagascar and the Seychelles . The Malabariinae, on the other hand, are native to India as far as the slopes of the Himalayas and to Myanmar .

The Ocnerodrilidae are usually semi aquatic soil inhabitants, and other such Crassiclitellaten substrate eaters which digest the organic components of the ingested substrate.

Genera

The family Ocnerodrilidae has two subfamilies with the following genera :

Ocnerodrilinae Beddard, 1891 (North America, Central America, South America, Africa)
Malabariinae Gates, 1966 (South Asia)

literature

  • Reginald William Sims (1981): A classification and the distribution of earthworms, suborder Lumbricina (Haplotaxida: Oligochaeta). Bulletin of the British Museum (Natural History), Zoology Series 39 (2), pp. 103–124, here p. 111.
  • Reginald William Sims, Brian M. Gerard: Earthworms: Keys and Notes for the Identification and Study of the Species. Doris M. Kermack, RSK Barnes (Ed.): Synopses of the British Fauna (New Series), No. 31. EJ Brill, London 1985. p. 123.