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Philometra Lethrini
''Philometra lethrini'' is a species of parasite, parasitic nematode of fishes, first found off New Caledonia in the South Pacific, in the gonads of ''Lethrinus genivittatus''. This species is characterized mainly by: length of spicules and length and structure of its gubernaculum, structure of male caudal end, body size, location in host and types of hosts. References Further reading * * Camallanida Parasitic nematodes of fish Nematodes described in 2008 {{Secernentea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
František Moravec (parasitologist)
František Moravec (born 1 January 1939) is a Czech parasitologist who specialises on the Nematodes, especially the nematodes fish parasites, parasites of fishes. His research is mainly in the field of taxonomy (biology), taxonomy of the Nematoda. Education and career Moravec was born on 1 January 1939 in Velká Bystřice. He was in high school in Olomouc then was a student in the Masaryk University in Brno, Czech Republic (at that time Czechoslovakia). For his Masters in 1962, he studied the parasitic worms of reptiles of Czechoslovakia. After graduation, he worked at the Institute of Parasitology of the Czech Academy of Sciences in České Budějovice, and in 1970 completed his thesis on nematodes parasites in fish. He is a world authority on Nematodes, especially their systematics and biology. Research Among the most important works by Moravec, Tomáš Scholz mentions his revision of the genera ''Rhabdochona'' and ''Anguillicola'', and also his clarification of the family Capi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Lou Justine
Jean-Lou Justine (born 1955), French parasitologist and zoologist, is a professor at the National Museum of Natural History (France), National Museum of Natural History in Paris, France, and a specialist of fish parasites and invasive species, invasive land planarians. Higher education and career Justine was in high school in Saint-Raphaël, Var, Saint Raphaël, France, then an undergraduate student at the University of Nice Sophia Antipolis, University of Nice (1972–1976), and at the École Normale Supérieure in Saint-Cloud after which he passed the ''Agrégation'' in 1977, and finally a graduate student at the University of Montpellier. He passed his PhD in 1980 and his ''Doctorat d'État'' (State doctorate) in 1985, both in the University of Montpellier, under the supervision of Professors Xavier Mattei and Louis Euzet. From 1978 to 1985, Justine was ''Assistant'' then ''Maître-Assistant'' (assistant professor) at the University of Dakar, Senegal. He entered the National M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasite
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of life. The entomologist E. O. Wilson characterised parasites' way of feeding as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as Armillaria mellea, honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the Orobanchaceae, broomrapes. There are six major parasitic Behavioral ecology#Evolutionarily stable strategy, strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), wikt:trophic, trophicallytransmitted parasitism (by being eaten), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (helminths) are the cause of soil-transmitted helminthiases. They are classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa. Unlike the flatworms, nematodes have a tubular digestive system, with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity suggested there are over 25,000. Estimates of the total number of extant species are su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Caledonia
New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of the French Republic, a legal status unique in overseas France, and is enshrined in a dedicated chapter of the French Constitution. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre (New Caledonia), Grande Terre, the Loyalty Islands, the Chesterfield Islands, the Belep archipelago, the Isle of Pines (New Caledonia), Isle of Pines, and a few remote islets. The Chesterfield Islands are in the Coral Sea. French people, especially locals, call Grande Terre , a nickname also used more generally for the entire New Caledonia. Kanak people#Agitation for independence, Pro-independence Kanak parties use the name (''pron.'' ) to refer to New Caledonia, a term coined in the 1980s from the ethnic name of the indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a Heterocrine gland, mixed gland and sex organ that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of Spermatozoon, spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals (and some humanssee Ovotesticular syndrome) have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone (LH) and follicle-stimulating hormone (FSH), produced and secreted by gonadotropic cell, gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone (GnRH) produced in the hypothalamus. Development The gonads develop f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lethrinus Genivittatus
''Lethrinus genivittatus'', the longspine emperor, threadfin emperor, lance emperor or lancer, is a species of fish in the genus ''Lethrinus'', and family Lethrinidae. It was first described by Achille Valenciennes in 1830. The IUCN classifies it as being of least concern. It lives in marine and brackish water and is native to the Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the s .... References genivittatus Fish of the Pacific Ocean Fish of the Indian Ocean Fish described in 1830 {{Acanthuriformes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gubernaculum
The paired gubernacula (from Ancient Greek κυβερνάω = pilot, steer), also called the caudal genital ligament, are embryonic structures which begin as undifferentiated mesenchyme attaching to the caudal end of the gonads (testicles in males and ovaries in females). Structure The gubernaculum is present only during the development of the reproductive system. It is later replaced by distinct vestiges in males and females. The gubernaculum arises in the upper abdomen from the lower end of the gonadal ridge and helps guide the testis in its descent to the inguinal region. Males * The upper part of the gubernaculum degenerates. * The lower part persists as the gubernaculum testis (" scrotal ligament"). This ligament secures the testis to the most inferior portion of the scrotum, tethering it in place and limiting the degree to which the testis can move within the scrotum. * Cryptorchidism (undescended testes) are observed in ''INSL3''-null male mice. This implicates INSL ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lethrinus Genivittatus JNC2640
''Lethrinus'' is a genus of marine ray-finned fishes belonging to the family Lethrinidae, the emperors and emperor breams. These fishes are mostly found in the Indian and western Pacific Oceans, with a single species in the eastern Atlantic Ocean. Taxonomy ''Lethrinus'' was first proposed as a genus in 1829 by the French zoologist Georges Cuvier. In 1912 David Starr Jordan and William Francis Thompson designated ''Sparus choerorynchus'' as the type species of the genus. ''Sparus choerorynchus'' had been described in 1801 by Marcus Elieser Bloch and Johann Gottlob Theaenus Schneider with its type locality given as Japan. ''Sparus choerorynchus'' is now considered to be a synonym of ''Lethrinus nebulosus'' (Forsskål 1775). Some authors place this genus in the monotypic subfamily Lethrininae, with all the other genera of Lethrinidae placed in the Monotaxinae, however, the 5th edition of ''Fishes of the World'' does not recognise the subfamilies traditionally accepted within the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camallanida
The Camallanida are an order of nematodes. They are parasites of terrestrial and aquatic vertebrates. They also use copepods as obligatory secondary hosts. They are sometimes included in the Spirurida as a suborder Camallanina. Description Amphid apertures of Camallaninas are pore or slit-like. Camallaninas have posterior phasmids. The excretory system of a Camallanina is tubular. Cuticles of Camallaninas are striated in two to four layers. Lateral field is present. Camallaninas have three esophageal glands. Their esophageal structure varies. Sensory papillae of Camallaninas are cephalic. Notable species and genera *''Dracunculus medinensis ''Dracunculus medinensis'' (Guinea worm, dragon worm, fiery serpent) is a nematode that causes dracunculiasis, also known as Guinea worm disease. The disease is caused by the female which, at around in length, is among the longest nematodes ...'' (human as final host) and '' Anguillicola crassus'' (eels as final host) are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Nematodes Of Fish
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of life. The entomologist E. O. Wilson characterised parasites' way of feeding as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as Armillaria mellea, honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the Orobanchaceae, broomrapes. There are six major parasitic Behavioral ecology#Evolutionarily stable strategy, strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), wikt:trophic, trophicallytransmitted parasitism (by being eaten), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
