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Topics related to "annelid"

Onychophora
Onychophora , small phylum with about 70 species of animals that are often called "missing links" between annelids (phylum Annelida ) and arthropods (phylum Arthropoda ). The thin cuticle and wormlike form of onychophorans are reminiscent of annelids, while the tracheal system and details of e... Read more
pseudocoelomate
pseudocoelomate , any of a group of invertebrates with a three-layered body that has a fluid-filled body cavity (pseudocoelom) between the endoderm and the mesoderm (the innermost and middle tissue layers). The pseudocoelom is contrasted with the coelom of mollusks, annelid worms, and the more compl... Read more
leech
leech predacious or parasitic annelid worm of the class Hirudinea, characterized by a cylindrical or slightly flattened body with suckers at either end for attaching to prey. The leech, like other annelids, is segmented, but its numerous surface folds obscure the internal segments. In many forms th... Read more
Annelida
Annelida [Lat., anellus =a ring], phylum of soft-bodied, bilaterally symmetrical (see symmetry, biological ), segmented animals, known as the segmented, or annelid, worms. Over 12,000 known species are grouped in three classes: the earthworms and freshwater worms (oligochaetes), the leeches (... Read more
bioluminescence
bioluminescence , production of light by living organisms. Organisms that are bioluminescent include certain fungi and bacteria that emit light continuously. The dinoflagellates, a group of marine algae, produce light only when disturbed. Bioluminescent animals include such organisms as ctenophores,... Read more
worm
worm common name for various unrelated invertebrate animals with soft, often long and slender bodies. Members of the phylum Platyhelminthes , or the flatworms, are the most primitive; they are generally small and flat-bodied and include the free-living planarians (of the class Turbellaria) as we... Read more
Nemertinea
Nemertinea , phylum of elongated, often flattened, marine Worms , sometimes called ribbon worms. There are 900 known species, ranging in size from a fraction of an inch to 90 ft (27 m). The most distinctive structure of the carnivorous ribbon worms is a proboscis that can be shot out to capture foo... Read more
Mollusca
Mollusca , taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,000 fossil species dating back to the Cambrian period. Mollusks are soft-bodied, and most have a prominent shell. The members... Read more
coral reefs
coral reefs limestone formations produced by living organisms, found in shallow, tropical marine waters. In most reefs, the predominant organisms are stony corals , colonial cnidarians that secrete an exoskeleton of calcium carbonate (limestone). The accumulation of skeletal material, broken and p... Read more
eye
eye organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of eye are the simple eye, found in many invertebrates, and the compound eye, found in insects and many other arthropods. In an alternate ... Read more

Encyclopedia entries related to "annelid"

annelid
Book article from: World Encyclopedia annelid Any member of the Annelida phylum of segmented worms . All have encircling grooves usually corresponding to internal partitions...
Annelida
Book article from: The Columbia Encyclopedia, Sixth Edition ...as the segmented, or annelid, worms. Over 12...worms (polychaetes). Annelids are found throughout...around themselves. Annelid Characteristics Segmented...the soft nature of the annelid body, fossils are not...swimming movements. Most annelids possess short external...
Paleontology
Encyclopedia entry from: The Gale Encyclopedia of Science ...into two evolutionary lines, the protostomes (molluscs, annelids, and arthropods) and the deuterostomes (echinoderms and...of invertebrate genetic material has shown that molluscs and annelids (segmented worms) probably evolved from arthropods. Neopilina...
Peanut Worms
Encyclopedia entry from: The Gale Encyclopedia of Science ...in the North Sea, Golfingia procera, is a predator on an annelid worm of the genus Aphrodite (known as a seamouse): it penetrates...the metanephridia. The nervous system resembles that of the annelid worms, but it is not segmented. The “ brain...
worm
Book article from: The Columbia Encyclopedia, Sixth Edition ...superstition had it that they developed from horsehairs. The annelid worms (phylum Annelida ) have segmented bodies, distinct...Oligochaeta, the leech (class Hirudinea), and the marine annelids of the class Polychaeta. The sea mouse , the clam worm, and...
Onychophora
Book article from: The Columbia Encyclopedia, Sixth Edition ...of animals that are often called "missing links" between annelids (phylum Annelida ) and arthropods (phylum Arthropoda...cuticle and wormlike form of onychophorans are reminiscent of annelids, while the tracheal system and details of embryonic development...
leech
Book article from: The Columbia Encyclopedia, Sixth Edition leech predacious or parasitic annelid worm of the class Hirudinea, characterized by a cylindrical or...suckers at either end for attaching to prey. The leech, like other annelids, is segmented, but its numerous surface folds obscure the internal...
arthropod
Book article from: World Encyclopedia ...arachnid , centipede , millipede , and insect . The species (numbering well over 1 million) are thought to have evolved from annelids . All have a hard outer skin of chitin that is attached to the muscular system on the inside. The body is divided into segments...
Respiration
Encyclopedia entry from: The Gale Encyclopedia of Science ...need. Microorganisms are able to use direct diffusion. Another rout of respiration involves diffusion of oxygen into blood. Annelids (segmented worms) and amphibians use this method, in which oxygen diffuses through a moist layer of epidermal cells on the...
Evolution, Evidence of
Encyclopedia entry from: The Gale Encyclopedia of Science ...structures. In embryology, the developing fetus is studied, and similarities with other organisms are observed. For example, annelids and mollusks are very dissimilar as adults. If, however, the embryo of a ragworm and a whelk are studied, one sees that...

Dictionary entries related to "annelid"

annelid
Book article from: The Oxford Pocket Dictionary of Current English an·ne·lid / ˈanlˌid / • n. any segmented worm of the phylum Annelida, including earthworms, lugworms, and leeches. • adj. of or relating to annelids.
Ivanov, Piotr Pavlovich
Dictionary entry from: Complete Dictionary of Scientific Biography ...embryology and regeneration of annelids. In 1912 at St. Petersburg...devoted to regeneration of annelids, and as associate professor...ontogenezu i morfologii annelid ( “ Regenerative Processes in Oligochaete Annelids and Their Relation to Ontogeny...
Hatschek, Berthold
Dictionary entry from: Complete Dictionary of Scientific Biography ...and metamorphosis of the larva of the annelids (or trochophores) and to formulate...trochophore stage is typical not only for the annelids but also for the mollusks, so that a...transitory phase of development for the annelids and mollusks, corresponded to a permanent...
Mesnil, Félix
Dictionary entry from: Complete Dictionary of Scientific Biography ...description of many new genera and species of annelids, crustaceans, enteropneusts, turbellarians...of investigations were devoted to the annelid polychaetes — to their morphology...the penetration of the larva into the annelid, and of its complex development. They...
M‘intosh, William Carmichael
Dictionary entry from: Complete Dictionary of Scientific Biography ...of his Monograph of the British Marine Annelids (The Nemerteam , published in two parts...brought him wide recognition; hence the Annelid collections from the Porcupine and Challenger...are: Monograph of the British Marine Annelids , 4 vols. (London, 1873 –...
Ediacaran fossils
Book article from: A Dictionary of Earth Sciences ...pennatulaceans (soft corals), e.g. Charniodiscus ; annelid worms, e.g. Spriggina ; and Dickinsonia , up to 1 m long...an anthozoan polyp, but has been variously assigned to the annelids, medusoids, and to a phylum of its own. There are also ovoid...
Archiannelida
Book article from: A Dictionary of Zoology ...Archiannelida (phylum Annelida ) A class of small, simple, annelid worms which are metamerically segmented (see METAMERIC SEGMENTATION...now suggest it represents an assortment of largely unrelated annelids, most of which are marine and members of the interstitial...
scolecodont
Book article from: A Dictionary of Earth Sciences scolecodont The pharyngeal jaws or maxillae of annelid worms ( Annelida ), commonly found in paired assemblages. They are usually black and chitinous and are known from most geologic systems .
Arthropoda
Book article from: A Dictionary of Ecology ...either from primitive polychaete worms or from ancestors common to both. Arthropods share several important features with annelid worms. The limbs of all arthropods are paired, jointed, and segmental, and the body has a chitinous exoskeleton. Primitively...
Polychaeta
Book article from: A Dictionary of Zoology ...species are hermaphrodites . Most are marine, although some occur in fresh water and on land. The group first appeared in the Cambrian (polychaetes are the only annelids to have a fossil record) and it contains more than 5000 species.

Related newspaper, magazine, and trade journal articles from HighBeam Research

Annelid phylogeny and the status of Sipuncula and Echiura.(Research article)
Magazine article from: BMC Evolutionary Biology; 4/5/2007; ; 700+ words ; ...with segmentation, annelids are critical in any...of groups within the annelid radiation if we are...body of data indicates annelid affinities for this...and Siboglinidae as annelids [7, 8, 9, 10, 11...Echiura possess annelid-like features such...
Muscle formation during embryogenesis of the polychaete Ophryotrocha diadema (Dorvilleidae) - new insights into annelid muscle patterns.(Research)
Magazine article from: Frontiers in Zoology; 1/2/2008; ; 700+ words ; ...comparative analysis of annelid muscle formation...knowledge base for annelids, and consequently...muscle arrangement in annelids, and annelid evolution [7, 34]. Current annelid phylogeny remains...plesiomorphic states in annelids [2, 21, 28...
Parasegmental appendage allocation in annelids and arthropods and the homology of parapodia and arthropodia.(Short report)(Report)
Magazine article from: Frontiers in Zoology; 10/20/2008; ; 700+ words ; ...body segments and appendages in annelids and arthropods might have originated...segmentation does not occur in annelids and the body units in annelids thus remain parasegments [6, 7]. This also makes annelid appendages (parapodia) parasegmental...
Size and organic content of eggs of marine annelids, and the underestimation of egg energy content by dichromate oxidation.
Magazine article from: The Biological Bulletin; 8/1/2004; ; 700+ words ; ...eggs of 12 species of marine annelids. In combination with measures...variables in 12 species of marine annelids, with the aim of testing hypotheses on differences between annelids and echinoderms in relationships...reviewed in ref. 1). Studied annelid eggs ranged in diameter from...
Annelid superhero back in 3-D game
Newspaper article from: New Straits Times; 2/3/2000; ; 700+ words ; ...Rahman New Straits Times 02-03-2000 Annelid superhero back in 3-D game Byline...a worm, and unbeknownst to our benign annelid friend, intergalactic battles were taking...he succeeds. So it would seem that our annelid friend is quite invincible. With that...
Rid sport of that annelid worm
Newspaper article from: New Straits Times; 1/29/2003; ; 700+ words ; ...Lazarus Rokk New Straits Times 01-29-2003 Rid sport of that annelid worm Byline: Lazarus Rokk Edition: Main/Lifestyle; 2...they have resembled the characteristics of that carnivorous annelid worm, commonly known to man as the leech. It's an embarrassment...
Molecular phylogeny of the model annelid ophryotrocha.
Magazine article from: The Biological Bulletin; 10/1/2001; ; 700+ words ; ...KENNETH M. HALANYCH (1) PER SUNDBERG (2) Introduction Marine annelids belonging to the group Ophryotrocha have been used as a laboratory...and Eide (1996) to reconstruct the phylogeny of this model annelid system so that knowledge gained about Ophryotrocha may be assessed...
Persistent ancestral feeding structures in nonfeeding annelid larvae.
Magazine article from: The Biological Bulletin; 12/1/2003; ; 700+ words ; ...distantly related to the echinoderms, the Annelida. Sabellid annelids are sessile, tube-dwelling worms often known as "feather...Rouse and Fitzhugh, 1994). A look at the relationships of annelid worms suggests that nonfeeding development in sabellids represents...
Polychaetous annelid assemblages associated with sediments near seven shallow wastewater outfalls along the Tijuana-Ensenada costal corridor in Northern Baja California, Mexico. (Abstracts).(Brief Article)
Magazine article from: Bulletin (Southern California Academy of Sciences); 8/1/2002; ; 700+ words ; ...habitats that occur near seven known point sources of wastewater discharge in the region. A total of 1,637 polychaetous annelids representing 31 families and 84 species were identified, which constituted 60% of all macrofauna sampled. Most abundant...
atonal - and achaete-scute -related genes in the annelid Platynereis dumerilii : insights into the evolution of neural basic-Helix-Loop-Helix genes.(Research article)
Magazine article from: BMC Evolutionary Biology; 6/9/2008; ; 700+ words ; ...which are derived characters specific to some bilaterian lineages, we have isolated and studied these genes in the polychaete annelid, Platynereis dumerilii , which belongs to a different branch (Trochozoa) of the bilaterians tree than Drosophila (Ecdysozoa...