|
Protocotyle Taschenbergi
''Protocotyle '' is a genus of monogeneans in the family Hexabothriidae. The genus was created by Louis Euzet and Claude Maillard in 1974. ''Protocotyle'' includes only three species, which are all parasitic on the gills of sharks of the genus '' Hexanchus'', namely '' Hexanchus griseus'' and '' Hexanchus nakamurai''. The species are: * ''Protocotyle euzetmaillardi ''Protocotyle euzetmaillardi'' is a species of monogenean of the family Hexabothriidae. It is the third described species of the genus '' Protocotyle'', after '' Protocotyle grisea'' (Cerfontaine, 1899) Euzet & Maillard, 1974Euzet, L. & Maillar ...'' Justine, 2011 * '' Protocotyle grisea'' (Cerfontaine, 1899) Euzet & Maillard, 1974 Cerfontaine, Paul. 1899: Contribution à l'étude des Octocotylidés. V. Les Onchocotylinae. Archives de Biologie, 16, 345-478 + Plates 18-21.Euzet, L. & Maillard, C. 1974: Les Monogènes Hexabothriidae Price, 1942. Historique, systématique, phylogenèse. Bulletin du Muséum National ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexanchus Nakamurai JNC2615 Body 1
The sixgill sharks are a genus, ''Hexanchus'', of deepwater sharks in the family Hexanchidae. These sharks are characterized by a broad, pointed head, six pairs of gill slits, comb-like, yellow lower teeth, and a long tail. The largest species can grow up to 8 m long and weigh over 600 kg (1320 lb). They are continental shelf-dwelling and abyssal plain scavengers with a keen sense of smell and are among the first to arrive at carrion, together with hagfish and rattails. They show a characteristic rolling motion of the head when feeding. They have been found at depths of up to . Though only two extant species (the bluntnose sixgill shark and the bigeyed sixgill shark) were originally known, a third, the Atlantic sixgill shark, was found to exist. Swimming behavior The bluntnose sixgill shark, ''Hexanchus griseus'', is relatively common to scientists. However, very little information exists about its distribution patterns, migrations and behavior. Data on occurr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monogenea
Monogeneans, members of the class Monogenea, are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they have both male and female reproductive structures.L.A. Tubbsa et al. (2005). "Effects of temperature on fecundity in vitro, egg hatching and reproductive development of ''Benedenia seriolae'' and ''Zeuxapta seriolae'' (Monogenea) parasitic on yellowtail kingfish Seriola lalandi". ''International Journal for Parasitology''(35), 315–327. Some monogeneans are oviparous (egg-laying) and some are viviparous (live-bearing). Oviparous varieties release eggs into the water. Viviparous varieties release larvae, which immediately attach to another host. The genus ''Gyrodactylus'' is an example of a viviparous variety, while the genus ''Dactylogyrus'' is an example of an oviparous variety. Signs and symptoms Freshwater fish that become infect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexabothriidae
Hexabothriidae is a family of monogenean parasites. The family name was proposed by Emmett W. Price in 1942.Price, E. W. 1942: North American monogenetic trematodes. V. The family Hexabothriidae n. n. (Polystomatoidea). Proceedings of the Helminthological Society of Washington, 9, 39-56PDF of entire volume The family includes 14-16 genus (biology), genera according to authors and about 60 species; all are parasitic on the gills of chondrichthyan fishes (ray (fish), rays, sharks and chimaeras). Studies on phylogeny of monogeneans based on morphology,Boeger, W. A., & Kritsky, D. C. (2001). Phylogenetic relationships of the Monogenoidea. In D. T. J. Littlewood & R. A. Bray (Eds.), Interrelationships of the Platyhelminthes (pp. 92-102). London & New York: Taylor and Francis molecules or spermatozoa suggest that the Hexabothriidae are a basal group within the Polyopisthocotylea. Genera ;According to the World Register of Marine Species Bray, R. (2004). WoRMS (2015). Hexabothriida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus (biology)
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demonstrate both monophyly and validity as a separate lineage). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Euzet
Louis Euzet (27 July 1923 in Lézignan-Corbières, France – 24 September 2013 in Sète, France) was a French parasitologist. Education Louis Euzet was a high-school student in Narbonne, France, and a student of the University of Montpellier (in the then “''Faculté des Sciences''”). He obtained his bachelor's degree (''Licence'') in 1947. He prepared his doctoral thesis in the Station de Biologie Marine at Sète, under the direction of Paul Mathias and Jean-George Baer; the thesis, on tetraphyllidean cestodes, was accepted on 16 June 1956. Career Louis Euzet was a junior lecturer at the Station de Biologie Marine in Sète in 1947. He was appointed Professor in the recently created “''Collège Scientifique Universitaire''” at Perpignan in 1959. He moved in 1969 to the University of Montpellier, where he established his ''Laboratoire de Parasitologie Comparée'' (Laboratory of Comparative Parasitology). He retired in 1991, became an Emeritus Professor in 1992 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill
A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia (: branchiae) is the zoologists' name for gills (from Ancient Greek ). With the exception of some aquatic insects, the filaments and lamella (surface anatomy), lamellae (folds) contain blood or Coelom#Coelomic fluid, coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including Mollusc, molluscs, crustaceans, insects, fish, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shark
Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the Division (taxonomy), division Selachii and are the sister group to the Batoidea, Batomorphi (Batoidea, rays and skate (fish), skates). Some sources extend the term "shark" as an informal category including Extinction, extinct members of Chondrichthyes (cartilaginous fish) with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as ''Cladoselache'' and ''Doliodus'' first appeared in the Devonian Period (419–359 million years), though some fossilized chondrichthyan-like scales are as old as the Ordovician, Late Ordovician (458–444 million years ago). The earliest confirmed modern sharks (Selachii) are known from the Early Jurassic around , with the oldest known member being ''Agaleus'', though records of true shar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexanchus
The sixgill sharks are a genus, ''Hexanchus'', of deepwater sharks in the family Hexanchidae. These sharks are characterized by a broad, pointed head, six pairs of gill slits, comb-like, yellow lower teeth, and a long tail. The largest species can grow up to 8 m long and weigh over 600 kg (1320 lb). They are continental shelf-dwelling and abyssal plain scavengers with a keen sense of smell and are among the first to arrive at carrion, together with hagfish and rattails. They show a characteristic rolling motion of the head when feeding. They have been found at depths of up to . Though only two extant species (the bluntnose sixgill shark and the bigeyed sixgill shark) were originally known, a third, the Atlantic sixgill shark, was found to exist. Swimming behavior The bluntnose sixgill shark, ''Hexanchus griseus'', is relatively common to scientists. However, very little information exists about its distribution patterns, migrations and behavior. Data on occurr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexanchus Griseus
The bluntnose sixgill shark (''Hexanchus griseus''), often simply called the cow shark, is the largest Hexanchiformes, hexanchoid shark, growing to in length. It is found in tropical and temperate waters worldwide and its diet is widely varied by region. The bluntnose sixgill is a species of sixgill sharks, of genus ''Hexanchus'', a genus that also consists of two other species: the bigeye sixgill shark (Bigeyed sixgill shark, ''Hexanchus nakamurai'') and the Atlantic sixgill shark (Atlantic sixgill shark, ''Hexanchus vitulus''). Through their base pairs of mitochondrial genes COI and ND2, these three species of sixgills widely differ from one another. Taxonomy The first scientific description of the bluntnose sixgill shark was authored in 1788 by Pierre Joseph Bonnaterre. As a member of the family (biology), family Hexanchidae, it has more close relatives in the fossil record than living relatives. The related living species include the Squaliformes, dogfish, the Greenland sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexanchus Nakamurai
The bigeyed sixgill shark (''Hexanchus nakamurai'') is a cow shark of the family Hexanchidae. Its dorsal surface has a brownish-gray color, and is sharply separated from the light coloring of its ventral surface. The eyes are a fluorescent green while the shark is alive. The body of this shark is small, slim, and fusiform in shape. As the name suggests, this shark has six gill slits, unusual among most shark species. The head is narrow and somewhat flattened, and the mouth contains 5 rows of large, comb-shaped teeth. This shark's single dorsal fin is pushed back towards the caudal fin, and is behind the pelvic fins. The upper caudal fin is much longer than the lower, with a deep notch near the tip. All fins have thin white margins on the edge. In juveniles, the upper caudal fin has a black tip. Measurements Length at birth for this species is 34–45 cm; adults average 1.2 m for both sexes, with a maximum of 1.8 m. Mature adults weigh around 20 kg. Range and habitat B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
