Pontoscolex

	Pontoscolex ''Pontoscolex'' is a genus of earthworms in the family Glossoscolecidae, or alternatively, in the family Rhinodrilidae. General characteristics The type species ''Pontoscolex corethrurus'' has a circumtropical distribution, although it originates in the Neotropics, probably in the Guiana Shield, Guiana Plateau. It reproduces Parthenogenesis, parthenogenetically, and under experimental conditions can complete its life cycle in about one year. Adults measure in length. Diagnostic characteristics There are eight setae per segment, arranged in regular rows, at least in the anterior part of the animal, whereas in the posterior part the arrangement varies (regular, more or less irregular, or in quincunx). No pigment is usually present. Male pores and tubercula pubertatis are in the Clitellum, clitellar region. The gizzard is in the segment VI. Three pairs of calciferous glands of tubular-dichotomous (panicled) structure are in the segments VII–IX. Earthworm#Form and function, Dorsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Pontoscolex Maracaensis ''Pontoscolex'' is a genus of earthworms in the family Glossoscolecidae, or alternatively, in the family Rhinodrilidae. General characteristics The type species '' Pontoscolex corethrurus'' has a circumtropical distribution, although it originates in the Neotropics, probably in the Guiana Plateau. It reproduces parthenogenetically, and under experimental conditions can complete its life cycle in about one year. Adults measure in length. Diagnostic characteristics There are eight setae per segment, arranged in regular rows, at least in the anterior part of the animal, whereas in the posterior part the arrangement varies (regular, more or less irregular, or in quincunx). No pigment is usually present. Male pores and tubercula pubertatis are in the clitellar region. The gizzard is in the segment VI. Three pairs of calciferous glands of tubular-dichotomous (panicled) structure are in the segments VII–IX. Dorsal, ventral, supra- and subesophageal and subneural vessels are pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Pontoscolex Corethrurus ''Pontoscolex corethrurus'' is an earthworm in the genus ''Pontoscolex''. It has a circumtropical distribution, although it originates in the Neotropics, probably in the Guiana Plateau. Description The worms are unpigmented and have around 200 segments. Adults measure in length. Reproduction It reproduces both parthenogenetically and (rarely) sexually, and under experimental conditions can complete its life cycle in about one year. Ecology and habitat The worm thrives in difficult environments with poor nutrition. It is key to emergence of agriculture in the Amazon Basin, where soil is extremely poor. It may have facilitated the formation of ''terra preta''. On the other hand, the worm's adaptability has allowed it to spread to many disturbed tropical areas, especially urban sites and industrially-farmed areas. It is now considered an invasive species in many parts of the world. An endogeic worm creating globular casts, it is considered responsible for soil compaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Glossoscolecidae The Glossoscolecidae are a large family of earthworms (annelids) which has native representatives in South and Central America. The species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ... '' Pontoscolex corethrurus'' has a circumtropical distribution. They are found mostly in forest, but one species of earthworms lives primarily in coastal beach sand. The earthworms in this family can reach up to 2 m in length. Selected genera * '' Andiorrhinus'' * '' Diaguita'' * '' Enantiodrilus'' * '' Eurydame'' * '' Fimoscolex'' * '' Glossodrilus'' * '' Glossoscolex'' * '' Holoscolex'' * '' Rhigiodrilus'' * '' Urochaeta'' * '' Pontoscolex'' References Haplotaxida Annelid families {{Annelid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Sphincter A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the human body, some microscopically small, in particular the millions of precapillary sphincters. Sphincters relax at death, often releasing Body fluid, fluids and faeces. Functioning Each sphincter is associated with the lumen (opening) it surrounds. As long as the sphincter muscle is contracted, its length is shortened and the lumen is constricted (closed). Relaxation of the muscle causes it to lengthen, opening the lumen and allowing the passage of liquids, solids, or gases. This is evident, for example, in the Blowhole (biology), blowholes of numerous marine mammals. Many sphincters are used every day in the normal course of digestion. For example, the lower oesophageal sphincter (or cardiac sphincter), which resides at the top of the stomach, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]