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Nealotus Tripes
The black snake mackerel (''Nealotus tripes'') is a species of snake mackerel found worldwide in both tropical and temperate waters where they are found at depths of from making diel vertical migrations from mesopelagic depths to the surface at night. It can reach a length of SL though most do not exceed SL. It is important to local peoples as a food fish. This species is currently the only known member of its genus, ''Nealotus''. That genus is therefore said to be monotypic. Parasites As all fish, the black snake mackerel has a variety of parasites. A study performed on fish from the subtropical upwelling region off North-West-Africa indicated that they harbour Myxozoa, Digenea, Monogenea, Cestoda, Nematoda including two species of ''Anisakis'', Acanthocephala, and Copepoda Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (living in the water column), some are benthic ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Yate Johnson
James Yate Johnson (c. 1820, in Kendal, Westmorland – 2 February 1900, in Funchal) was an English naturalist. Johnson lived in Madeira from around 1851, studied marine fish, crustacea, sea anemones and sponges and terrestrial spiders, flowering plants and mosses. He collected specimens for other naturalists; for instance, George Busk, who in 1859 wrote "Zoophytology: On some Madeiran Polyzoa." Collected by J. Yates Johnson, Esq. in the ''Quarterly Journal of Microscopical Science'', vol. 7, pp. 65–67. He discovered '' Halargyreus johnsonii'' and '' Melanocetus johnsonii'' Günther, 1864 during his time in Madeira. Johnson explored the São Vicente Caves after being informed of their existence by locals on Madeira in 1885. The caves were opened to the public on 1 October 1996, being one of the first caves of volcanic origins to be opened to the public in Portugal. Family He was the son of John Henry Johnson and Ann Yate, also brother of John Henry Johnson (patent a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxozoa
Myxozoa (etymology: Greek: μύξα ''myxa'' "slime" or "mucus" + thematic vowel o + ζῷον ''zoon'' "animal") is a subphylum of aquatic cnidarian animals – all obligate parasites. It contains the smallest animals ever known to have lived. Over 2,180 species have been described and some estimates have suggested at least 30,000 undiscovered species. Many have a two-host lifecycle, involving a fish and an annelid worm or a bryozoan. The average size of a myxosporean spore usually ranges from 10 μm to 20 μm, whereas that of a malacosporean (a subclade of the Myxozoa) spore can be up to 2 mm. Myxozoans can live in both freshwater and marine habitats. Myxozoans are highly derived cnidarians that have undergone dramatic evolution from a free swimming, self-sufficient jellyfish-like creature into their current form of obligate parasites composed of very few cells. As myxozoans evolved into microscopic parasites, they lost many genes responsible for multice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copepoda
Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (living in the water column), some are benthic (living on the sediments), several species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, puddles, damp moss, or water-filled recesses of plants ( phytotelmata) such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as biodiversity indicators. As with other crustaceans, copepods have a larval form. For copepods, the egg hatches into a nauplius form, with a head and a tail but no true thorax or abdomen. The larva molts several times until it resembles the adult and then, after more molts, achieves adult development. The nauplius form is so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthocephala
Acanthocephala ( Greek , ' 'thorn' + , ' 'head') is a group of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host. Acanthocephalans have complex life cycles, involving at least two hosts, which may include invertebrates, fish, amphibians, birds, and mammals. About 1,420 species have been described. The Acanthocephala were long thought to be a discrete phylum. Recent genome analysis has shown that they are descended from, and should be considered as, highly modified rotifers. This unified taxon is sometimes known as Syndermata, or simply as Rotifera, with the acanthocephalans described as a subclass of a rotifer class Hemirotatoria. History The earliest recognisable description of Acanthocephala – a worm with a proboscis armed with hooks – was made by Italian author Francesco Redi (1684). In 1771 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisakis
''Anisakis'' ( ) is a genus of parasitic nematodes that have life cycles involving fish and marine mammals. They are infective to humans and cause #Anisakiasis, anisakiasis. People who produce immunoglobulin E in response to this parasite may subsequently have an allergic reaction, including anaphylactic, anaphylaxis, after eating fish infected with ''Anisakis'' species. Etymology The genus ''Anisakis'' was defined in 1845 by Félix Dujardin as a subgenus of the genus (biology), genus ''Ascaris'' Carl Linnaeus, Linnaeus, 10th edition of Systema Naturae, 1758. Dujardin did not make explicit the etymology, but stated that the subgenus included the species in which the males have unequal spicule (nematode), spicules ("''mâles ayant des spicules inégaux''"); thus, the name ''Anisakis'' is based on ''anis-'' (Greek prefix for different) and ''akis'' (Greek for spine or spicule). Two species were included in the new subgenus, ''Ascaris'' (''Anisakis'') ''distans'' Karl Asmund Rudolph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematoda
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 parasitism, parasitic. Parasitic worms (helminths) are the cause of Soil-transmitted helminthiasis, soil-transmitted helminthiases. They are classified along with arthropods, tardigrades and other moulting animalia, animals in the clade Ecdysozoa. Unlike the flatworms, nematodes have a tubular digestion, 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. Es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cestoda
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, commonly known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed into the environment to infect other organisms. Species of the other subclass, Cestodaria, are mainly fish-infecting parasites. All cestodes are parasitic; many have complex life histories, including a stage in a definitive (main) host in which the adults grow and reproduce, often for years, and one or two intermediate stages in which the larvae develop in other hosts. Typically the adults live in the digestive tracts of vertebrates, while the larvae often live in the bodies of other animals, either vertebrates or invertebrates. For example, '' Diphyllobothrium'' has at least two intermediate hosts, a crustacean and then one or mo ... [...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] |
Digenea
Digenea (Gr. ''Dis'' – double, ''Genos'' – race) is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms (known as ''flukes'') with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date. Morphology Key features Characteristic features of the Digenea include a syncytial tegument; that is, a tegument where the junctions between cells are broken down and a single continuous cytoplasm surrounds the entire animal. A similar tegument is found in other members of the Neodermata; a group of platyhelminths comprising the Digenea, Aspidogastrea, Monogenea and Cestoda. Digeneans possess a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With nearly billion people as of , it accounts for about of the world's human population. Demographics of Africa, Africa's population is the youngest among all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Based on 2024 projections, Africa's population will exceed 3.8 billion people by 2100. Africa is the least wealthy inhabited continent per capita and second-least wealthy by total wealth, ahead of Oceania. Scholars have attributed this to different factors including Geography of Africa, geography, Climate of Africa, climate, corruption, Scramble for Africa, colonialism, the Cold War, and neocolonialism. Despite this lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Douglas Ogilby
James Douglas Ogilby (16 February 1853 – 11 August 1925) was an Australian ichthyologist and herpetologist. Ogilby was born in Belfast, Ireland, and was the son of zoologist William Ogilby and his wife Adelaide, née Douglas. He received his education at Winchester College, England, and Trinity College, Dublin. Ogilby worked for the British Museum before joining the Australian Museum in Sydney. After being let go for drunkenness in 1890, he picked up contract work before joining the Queensland Museum in Brisbane circa 1903. He was the author of numerous scientific papers on reptiles, and he described a new species of turtle and several new species of lizards. Death Ogilby died on 11 August 1925 at the Diamantina Hospital in Brisbane and was buried at Toowong Cemetery. Legacy Numerous species of fish were named in Ogilby's honor: *''Callionymus ogilbyi'' (Rayfinned Fish) *''Calliurichthys ogilbyi'' (Ogilby’s Stinkfish) *''Cynoglossus ogilbyi'' (Tongue Sole) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upwelling
Upwelling is an physical oceanography, oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll a. The increased availability of nutrients in upwelling regions results in high levels of primary production and thus fishery production. Approximately 25% of the total global marine fish catches come from five upwellings, which occupy only 5% of the total ocean area.Jennings, S., Kaiser, M.J., Reynolds, J.D. (2001) "Marine Fisheries Ecology." Oxford: Blackwell Science Ltd. Upwellings that are driven by coastal ocean curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
