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Chaetognatha
Chaetognatha , phylum of predominantly pelagic marine animals commonly known as arrowworms. Arrowworms have slender, transparent bodies, usually under 1 in. (2.5 cm) long. Lateral and caudal fins propel the animal in sudden darting movements. The well-developed head bears eyes and other sense organs, grasping spines used in the capture of prey, and rows of teeth flanking the mouth. A protective hood can be folded down over the bristles and teeth. The digestive system includes a glandular pharynx, a straight intestine, and a short, muscular rectum. The nervous system centers in a bilobed, dorsal brain and several other nerve ganglia. Although widely distributed, arrowworms prefer warm, shallow seas and are particularly plentiful in the Indo-Pacific region. They are voracious predators; some feed on freshly hatched fish nearly as large as themselves. They are influential planktonic consumers when abundant. |
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"Chaetognatha." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "Chaetognatha." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1E1-Chaetogn.html "Chaetognatha." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-Chaetogn.html |
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Chaetognatha
Chaetognatha A phylum that comprises the ‘arrow worms’, first encountered in the fossil record in Carboniferous rocks. They are characterized by the possession of horizontal fins that flank the trunk and tail. The body is semi-transparent, streamlined, and divided into a head, trunk, and post-anal tail region. The head bears eyes and food-catching spines. Arrow worms are common among marine plankton.
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MICHAEL ALLABY. "Chaetognatha." A Dictionary of Zoology. 1999. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Chaetognatha." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O8-Chaetognatha.html MICHAEL ALLABY. "Chaetognatha." A Dictionary of Zoology. 1999. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-Chaetognatha.html |
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Chaetognatha
Chaetognatha A phylum of marine coelomate invertebrates, the arrow worms, in which the head bears hooks for catching prey and the trunk and tail support paired lateral and tail fins. They lack organs for excretion, circulation, and respiration and are hermaphrodite.
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"Chaetognatha." A Dictionary of Biology. 2004. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "Chaetognatha." A Dictionary of Biology. 2004. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O6-Chaetognatha.html "Chaetognatha." A Dictionary of Biology. 2004. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-Chaetognatha.html |
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Chaetognatha
Chaetognatha Phylum comprising the arrow worms, first encountered in the fossil record in Carboniferous rocks.
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AILSA ALLABY and MICHAEL ALLABY. "Chaetognatha." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Chaetognatha." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O13-Chaetognatha.html AILSA ALLABY and MICHAEL ALLABY. "Chaetognatha." A Dictionary of Earth Sciences. 1999. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Chaetognatha.html |
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