placoid scale
placoid scale (dermal denticle) Type of scale that comprises the basic unit of the hard skin cover of sharks. It consists of a hard base embedded in the skin and a spiny process (cusp); these are covered by a hard, enamel-like substance (vitrodentine), and the scale projects outwards and backwards. The bulk of the denticle consists of
dentine surrounding a central pulp cavity. Unlike the scales of
bony fish, placoid scales stop growing after they reach a certain size and new denticles are added instead.
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Pacific hagfish, Eptatretus stouti, and black hagfish, E. deani: the Oregon Fishery and Port sampling observations, 1988-92.
Magazine article from: Marine Fisheries Review; 9/22/1993; ; 700+ words
; Introduction Hagfish, Eptatretus spp., of the class Agnatha...are separate, and both male and female hagfish have a single gonad. During each spawning...fertilized after extrusion (Jensen, 1966). Hagfish have numerous glands along both sides...
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Researchers Seek Secrets of Hagfish
News Wire article from: AP Online; 5/19/2002; ; 700+ words
; ...to unravel the slimy mysteries of the hagfish, one of the sea' s oldest and oddest...reproduction. No one has found a fertilized hagfish egg in the last 100 years, said Stacia...other fish have dwindled, the strange hagfish have become one of New England's newest...
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Researchers seek secrets of hideous hagfish, New England's newest fishery
News Wire article from: AP Worldstream; 5/23/2002; ; 700+ words
; ...to unravel the slimy mysteries of the hagfish, one of the sea' s oldest and oddest...reproduction. No one has found a fertilized hagfish egg in the last 100 years, said Stacia...other fish have dwindled, the strange hagfish have become one of New England's newest...
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Fine structure of spermatozoa of the hagfish Eptatretus burgeri (Agnatha).
Magazine article from: The Biological Bulletin; 8/1/1995; ; 700+ words
; ...reproduction, especially fertilization, in hagfish (Dean, 1899; Walvig, 1963; Gorbman...structures of the testes and spermatozoa of hagfish have been described in Myxine glutinosa...studies on the formation and structure of hagfish spermatozoa in Myxine circifrons, M...
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North Sider's hagfish fossil find is really one for the books
Newspaper article from: Chicago Sun-Times; 11/1/1991; ; 656 words
; ...science today shines upon the plug-ugly hagfish - a scaleless, soft-skinned scavenger...confirmed to be a 300-million-year-old hagfish, the oldest ever. "I didn't even know what a hagfish was at the time," said Sroka, who found...
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A hagfish by any other name would not smell as sweet.(RESEARCH NEWS)
Magazine article from: Oceanus; 7/1/2007; ; 700+ words
; It's not hard to figure out how hagfish got their name, as they aren't exactly...expedition south of Easter Island was the first hagfish captured from a hydrothermal vent site...what researchers had then suspected: The hagfish was a new species, and one of the deepest...
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A New Species of Hagfish (Myxinidae: Eptatretus) Associated with Deep-Sea Coral Habitat in the Western North Atlantic
Magazine article from: Copeia; 3/21/2008; ; 700+ words
; ...color. Eptatretus lopheliae is a small hagfish species observed, videotaped, and caught...with Lophelia pertusa reef habitat. THE hagfish family Myxinidae is composed of two subfamilies...describe a new species of five-gilled hagfish, Eptatretus lophellae, which was collected...
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A New Species of Giant Seven-gilled Hagfish (Myxinidae: Eptatretus) from New Zealand
Magazine article from: Copeia; 5/26/2006; ; 700+ words
; ...and 6.2 kg, is the largest hagfish yet known. THE seven-gilled hagfishes of the genus Eptatretus (Myxinidae...had been the largest known hagfish, with nine specimens measuring...specimen of an extremely large hagfish was taken off northeastern...
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Hagfish named after discoverer Submarine pilot found it in Pacific
Newspaper article from: The Boston Globe; 2/19/2007; ; 509 words
; ...his name. Behold the latest species of hagfish, the Eptatretus strickrotti. "I'm...Oceanographic Institution, discovered the hagfish in March 2005, while plumbing the inky...that the fish was a new member of the hagfish family and one of the deepest-dwelling...
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Ikaros proteins discovered in hagfish and urochordate.
Newspaper article from: Health & Medicine Week; 1/5/2004; 700+ words
; ...proteins have been identified in species of hagfish and urochordate, shedding new light on...like (IFL) protein from the agnathan hagfish Myxine glutinosa and the marine urochordate...showed. "Expression of the IFL gene in hagfish was strongest in blood, intestine, and...
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Lampreys and Hagfishes
Encyclopedia entry from: The Gale Encyclopedia of Science
...environment through gill slits. Hagfishes have four distinct blood...describe the method by which hagfish eggs get fertilized. This prize has yet to be claimed! Hagfish feed largely on invertebrates...inside out. Hatchlings of hagfishes resemble the adults, and therefore...
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Hagfish
Encyclopedia entry from: The Gale Encyclopedia of Science
Hagfish A primitive group of fish, hagfish (order Hyperotreti, family Myxinidae) resemble eels in their...1.5 feet (40 cm); females are often larger than males. Hagfish are bottom-dwelling fish of soft, muddy substrates, living...
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hagfish
Book article from: The Columbia Encyclopedia, Sixth Edition
...system, a spleen, and scales. Hagfish, or hags, spend much time...Also known as slime eels, hagfish have glands on either side of...genera and about 20 species of hagfishes. The Atlantic hagfish, Myxine glutinosa, may reach...
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Agnatha
Book article from: Animal Sciences
...have survived to the present, the lampreys and the hagfish. Characteristics of Agnathans As the most primitive...groups. The second group of living agnathans is the hagfish. Hagfish are scavenger species that feed off dead and wounded...
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Cyclostomata
Book article from: A Dictionary of Zoology
...extant orders usually included are the lampreys (Petromyzoniformes) and the hagfish (Myxiniformes) but there is now considerable doubt whether they are closely related to each other; the hagfish may be a sister group to other vertebrates.
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