Definitions for annelida
an·nel·i·da

Princeton's WordNetRate this definition:1.0 / 1 vote

1. Annelida, phylum Annelidanoun

   segmented worms: earthworms; lugworms; leeches

WikipediaRate this definition:0.0 / 0 votes

1. Annelida

   The annelids (Annelida , from Latin anellus, "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychaetes. Annelids are considered members of the Lophotrochozoa, a "super-phylum" of protostomes that also includes molluscs, brachiopods, and nemerteans. The basic annelid form consists of multiple segments. Each segment has the same sets of organs and, in most polychates, has a pair of parapodia that many species use for locomotion. Septa separate the segments of many species, but are poorly defined or absent in others, and Echiura and Sipuncula show no obvious signs of segmentation. In species with well-developed septa, the blood circulates entirely within blood vessels, and the vessels in segments near the front ends of these species are often built up with muscles that act as hearts. The septa of such species also enable them to change the shapes of individual segments, which facilitates movement by peristalsis ("ripples" that pass along the body) or by undulations that improve the effectiveness of the parapodia. In species with incomplete septa or none, the blood circulates through the main body cavity without any kind of pump, and there is a wide range of locomotory techniques – some burrowing species turn their pharynges inside out to drag themselves through the sediment. Earthworms are oligochaetes that support terrestrial food chains both as prey and in some regions are important in aeration and enriching of soil. The burrowing of marine polychaetes, which may constitute up to a third of all species in near-shore environments, encourages the development of ecosystems by enabling water and oxygen to penetrate the sea floor. In addition to improving soil fertility, annelids serve humans as food and as bait. Scientists observe annelids to monitor the quality of marine and fresh water. Although blood-letting is used less frequently by doctors than it once was, some leech species are regarded as endangered species because they have been over-harvested for this purpose in the last few centuries. Ragworms' jaws are now being studied by engineers as they offer an exceptional combination of lightness and strength. Since annelids are soft-bodied, their fossils are rare – mostly jaws and the mineralized tubes that some of the species secreted. Although some late Ediacaran fossils may represent annelids, the oldest known fossil that is identified with confidence comes from about 518 million years ago in the early Cambrian period. Fossils of most modern mobile polychaete groups appeared by the end of the Carboniferous, about 299 million years ago. Palaeontologists disagree about whether some body fossils from the mid Ordovician, about 472 to 461 million years ago, are the remains of oligochaetes, and the earliest indisputable fossils of the group appear in the Paleogene period, which began 66 million years ago.

ChatGPTRate this definition:0.0 / 0 votes

1. annelida

   Annelida is a large phylum of segmented worms, containing over 22,000 species including earthworms, ragworms, and leeches. Annelids are found in most wet environments, and include forms that are free-living, tubicolous, burrowing or parasitic. They are characterized by a segmented body, a well-developed coelom (body cavity), often complex setae (bristles) and paired appendages, and a digestive system that is complete and runs through the middle of the body. Their name comes from the Latin word "annelus" which means "little ring", referring to their ring-like segmented appearance.

Webster DictionaryRate this definition:4.5 / 2 votes

1. Annelida

   a division of the Articulata, having the body formed of numerous rings or annular segments, and without jointed legs. The principal subdivisions are the Chaetopoda, including the Oligochaeta or earthworms and Polychaeta or marine worms; and the Hirudinea or leeches. See Chaetopoda

2. Etymology: [NL. See Annelid.]

Chambers 20th Century DictionaryRate this definition:4.0 / 1 vote

1. Annelida

   an-el′i-da, n. a class of animals comprising the red-blooded worms, having a long body composed of numerous rings.—n. Ann′elid. [L. annellus, dim. of annulus, a ring.]

U.S. National Library of MedicineRate this definition:0.0 / 0 votes

1. Annelida

   A phylum of metazoan invertebrates comprising the segmented worms, and including marine annelids (POLYCHAETA), freshwater annelids, earthworms (OLIGOCHAETA), and LEECHES. Only the leeches are of medical interest. (Dorland, 27th ed)

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1. • Phylum

How to pronounce annelida?

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Numerology

1. Chaldean Numerology

   The numerical value of annelida in Chaldean Numerology is: 7

2. Pythagorean Numerology

   The numerical value of annelida in Pythagorean Numerology is: 6

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References

1. ^ Princeton's WordNet
   http://wordnetweb.princeton.edu/perl/webwn?s=annelida
2. ^ Wikipedia
   https://en.wikipedia.org/wiki/Annelida
3. ^ ChatGPT
   https://chat.openai.com
4. ^ Webster Dictionary
   https://www.merriam-webster.com/dictionary/annelida
5. ^ Chambers 20th Century Dictionary
   https://www.gutenberg.org/files/37683/37683-h/37683-h.htm#:~:text=annelida