Meanings Of Locomotion In An Earthworm
← Locomotion means the act / power of moving from place to place, characteristic of the higher animals and some of the lower forms of plant life.
← Earthworm is any one of numerous annelid worms that burrow in soil and feed on soil nutrients and decaying organic matter or any worm of the genus Lumbricus and allied genera, found in damp soil.
Taxonomy and Geographic Origins Of Earthworm
← L.Terestris : Europe and America.
← Angleworm/Fishworm (used bait for angling) : Northern and Midland U.S and New England. ← Fishing Worm : Midland and Southern U.S.
← Wiggler : Southern U.S.
← Nightwalker : New England.
← Nightcrawler : Northern, North Midland and Western U.S. ← Dew Worm : Inland North and Canada.
← Red Worm : North Central, South Midland and Southern U.S. ← Lumbricidae : Temperate Northern Hemisphere from Vancouver Island, Canada to Japan, mostly Eurasia. ← Hormogastridae : Europe.
← Sparganophilidae : North America.
← Almidae : Africa, South America.
← Ocnerodrilidae : Central and South America, Africa.
← Acanthodrilidae : Africa, midland and southeastern North America, Central and South America, Australia and Oceania. ← Octochaetidae : Central/South America, western Africa, India, New Zealand, Australia. ← Exxidae : Central America/Caribbean.
← Megascolecidae : South East Asia, Australasia and Oceania, northwestern North America. ← Glossoscolecidae : Central and northern South America. ← Eudrilidae : Tropical Africa.
Earthworm Locomotion and Its Importance To Soil
Lumbricus (earthworm) is an example of the phylum Annelida. The body of annelids is divided into sections by septa (membranes). Each section is a compartment. Its movement is a result of the action of body-wall muscles on incompressible fluids in the compartments (segments). Therefore, a compartment that contracts in diameter must simultaneously increase in length. There are three classes in this phylum. Class Oligochaeta includes the earthworm; they are usually found in fresh water or moist soil, lack a well-developed head, and have few setae per segment. Earthworm activity aerates and mixes the soil, and is constructive to mineralization and nutrient uptake by vegetation. Certain species of earthworm come to the surface and graze on the higher concentrations of organic matter present there, mixing it with the mineral soil. Because a high level of organic matter mixing is associated with soil fertility, an abundance of earthworms is beneficial to the organic gardener. In fact as long ago as 1881 Charles Darwin wrote: “It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures “ (The Formation Of Vegetable Mould Through The Action Of Worms, Charles Darwin)
Anatomy Of Earthworm
The basic body plan of an earthworm is a tube, the digestive system, within a tube, the muscular slimy, moist outer body. The body is annular, formed of segments that are most specialized in the anterior. Earthworms have a simple circulatory system. They have two main blood vessels that extend through the length of their body: a ventral blood vessel which leads the blood to the posterior end, and a dorsal blood vessel which leads to the anterior end. The dorsal vessel is contractile and pumps blood forward, where it is pumped into the ventral vessel by a series of "hearts" (aortic arches) which vary in number in the different taxa. A typical lumbricid will have 5 hearts. The blood is distributed from the ventral vessel into capillaries on the body wall and other organs and into a vascular sinus in the gut wall, where gases and nutrients are exchanged. This arrangement may be complicated in the various groups by suboesophageal, supraoesophageal, parietal and neural vessels, but the basic arrangement holds in all earthworms. These single celled earthworms...
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