Megascolecidae

Megascolecidae
Megascolecidae castings in India
Scientific classification
Kingdom:	Animalia
Subkingdom:	Eumetazoa
Phylum:	Annelida
Class:	Clitellata
Subclass:	Oligochaeta
Order:	Haplotaxida
Suborder:	Lumbricina
Family:	Megascolecidae
Genera
Over 65, see text

Megascolecidae is a large family of earthworms which has native representatives in Australia, New Zealand, Southeast and East Asia, and North America. The most ancient lineages of the family show a Gondwanan distribution and have been used as evidence of continental drift. Members of the Pheretima group of genera (e.g. Amynthas) are widely distributed around the tropics, much as some Lumbricidae are distributed through the temperate zones. Some North American native genera – e.g. Arctiostrotus, Argilophilus and Driloleirus – also belong to this family.

The members of this family have the typical "megascolecine" arrangement of male pores, with vasa deferentia and prostatic ducts uniting before opening via a combined pore on segment 18, rather than the "acanthodriline" arrangement (with male pores and pores from one or more pairs of prostates opening separately near segment 18, but never combined on segment 18) as found in the related families Acanthodrilidae, Octochaetidae and Exxidae.

Megascolecidae genera are either meroic (with multiple nephridia per segment), or have the plesiomorphic holoic arrangement of two nephridia per segment. Some taxa also exhibit enteronephry, where some nephridia, instead of emptying to the body surface, empty into the digestive tract. Setae may be lumbricine (plesiomorphic, 8 per segment) or perichaetine (more than 8 setae per segment).

Selected genera

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Amynthas Anisochaeta Beddard, 1890 Arctiostrotus Argilophilus Balanteodrilus Begemius Borgesia Celeriella Gates, 1958 Chetcodrilus Comarodrilus Cryptochaeta Cryptodrilus Dendropheretima Deodrilus Didymogaster Digaster Diporochaeta Drilocheira Driloleirus Duplodicodrilus Eastoniella Ephemitra Eudiplotrema Fletcherodrilus Graliophilus Hegesipyle Heteroporodrilus Hickmaniella Hypolimnus Isarogoscolex Kanchuria Kincaidodrilus Lampito Lennoscolex

Macnabodrilus Megascolex Megascolides Metapheretima Metaphire Nelloscolex Neotrigaster Nephrallaxis Notoscolex Parapheretima Paraplutellus Perionychella Perionyx Perissogaster Pheretima Pithemera Planapheretima Pleionogaster Pleurochaeta Plutellus Polypheretima Pontodrilus Promegascolex Reflechtodrilus Sebbius Simsia Spenceriella[verification needed] Tonoscolex Toutellus Troyia Vesiculodrilus Woodwardiella Zapatodrilus

External links

• WikiSpecies