Megascolex

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Megascolex
Systematics
Trunk : Annelids (Annelida)
Class : Belt worms (Clitellata)
Order : Little bristle (Oligochaeta)
Family : Megascolecidae
Genre : Megascolex
Scientific name
Megascolex
Templeton , 1844

Megascolex (from the Greek μέγας mégas "large" and σκώληξ skṓlēx "worm") is a genus of little bristles from the family of Megascolecidae (giantearthworms) in the order of Crassiclitellata (earthworms in the broader sense), of which over a hundred species are describedin the tropics with a focus on Asia .

features

The giant earthworms of the genus Megascolex have cylindrical bodies that can reach lengths from several centimeters to over a meter. A row of numerous bristles runs around each segment, each of which is interrupted by a center line on the stomach and back. The intestinal canal has a chewing stomach in front of the 7th segment and has no blind sacs. The nephridia are diffuse cluster-shaped.

The clitellum always comprises more than three segments. The two male genitals of the hermaphrodites are located on the abdomen on the 18th segment, the unpaired female genitals on the 14th segment. There are 1 to 5 pairs of receptacula seminis , the exits of which are located on the side to the middle of the abdomen between the 4th and 9th segment. Penis bristles are provided.

Development cycle

Like all girdle worms , the giant earthworms of the genus Megascolex are hermaphrodites and reproduce sexually through mutual copulation, with the sperm of the respective sex partner being stored in the receptacula seminis . With the help of the short clitellum , cocoons are formed, in which both mothers lay their eggs and inseminate them with the sperm of their sex partner. The embryos develop into finished earthworms in the cocoon.

Habitat and way of life

The Megascolex -Regenwürmer as other Crassiclitellaten soil inhabitants and substrate eaters which digest the organic components of the ingested substrate.

Sample species and their distribution

The first species to be described by Robert Templeton in 1844 was the species Megascolex caeruleus , native to the lowland rainforests of Sri Lanka , which, with lengths of up to one meter, is one of the very large earthworm species and is striking due to its blue color.

species

The following species have been described in the genus Megascolex , of which 33 species have so far been recorded in India alone :

literature