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Philometra Priacanthi
''Philometra priacanthi'' is a species of parasitic nematode of fishes. Its name is derived from its host species, '' Priacanthus hamrur''. It possesses dorsal lamella-like structures on the distal part of its gubernaculum, which can also be found on other of its cogenerates. The only species with a dorsal protuberance near the gubernaculum's end is ''P. priacanthi'', however. '' P. lateolabracis'' can be distinguished from the former by the lateral caudal mounds separated dorsally, narrower lamella-like structures on its gubernaculum, shorter spicules, and by the testis extending anteriorly. Other gonad-infecting species differ from this one by possessing a smooth gubernaculum, and their spicules being of different lengths. Seven gonad-infecting species of ''Philometra'' can be distinguished from ''P. priacanthi'' by their host types, as well as by geographical distribution. Description This description is based on a male specimen. It presents a filiform, whitish body, me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spicule (nematode)
In nematodes, spicules, also known as copulatory spicules, are needle-like mating structures found only in males. Male nematodes may have one or two spicules which serve to open the vulva of females and facilitate the transmission of sperm, although sperm is not transferred directly by or through the spicules.Chitwood, B. G. & Chitwood, M. B. (1950). Introduction to Nematology (Vol. 1). Baltimore: Monumental Printing Co. (Function of spicule: pages 123-124) The gubernaculum is another organ of the nematode male copulatory system which guides the spicules during copulation. References Nematode anatomy Animal male reproductive system {{nematode-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Caledonia
) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign state , subdivision_name = , established_title = Annexed by France , established_date = 24 September 1853 , established_title2 = Overseas territory , established_date2 = 1946 , established_title3 = Nouméa Accord , established_date3 = 5 May 1998 , official_languages = French , regional_languages = , capital = Nouméa , coordinates = , largest_city = capital , demonym = New Caledonian , government_type = Devolved parliamentary dependency , leader_title1 = President of France , leader_name1 = Emmanuel Macron , leader_title2 = President of the Government , leader_name2 = Louis Mapou , leader_title3 = President of the Congress , leader_name3 = Roch Wamytan , leader_title4 = High Commissioner , leader_name4 = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nouméa
Nouméa () is the capital and largest city of the French special collectivity of New Caledonia and is also the largest francophone city in Oceania. It is situated on a peninsula in the south of New Caledonia's main island, Grande Terre, and is home to the majority of the island's European, Polynesian ( Wallisians, Futunians, Tahitians), Indonesian, and Vietnamese populations, as well as many Melanesians, Ni-Vanuatu and Kanaks who work in one of the South Pacific's most industrialised cities. The city lies on a protected deepwater harbour that serves as the chief port for New Caledonia. At the September 2019 census, there were 182,341 inhabitants in the metropolitan area of Greater Nouméa (), 94,285 of whom lived in the city ( commune) of Nouméa proper. 67.2% of the population of New Caledonia live in Greater Nouméa, which covers the communes of Nouméa, Le Mont-Dore, Dumbéa and Païta. History The first European to establish a settlement in the vicinity was Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a mixed gland 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 spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals 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 and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus. Development Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges, which ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclera
The sclera, also known as the white of the eye or, in older literature, as the tunica albuginea oculi, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some crucial elastic fiber. In humans, and some other vertebrates, the whole sclera is white, contrasting with the coloured iris, but in most mammals, the visible part of the sclera matches the colour of the iris, so the white part does not normally show while other vertebrates have distinct colors for both of them. In the development of the embryo, the sclera is derived from the neural crest. In children, it is thinner and shows some of the underlying pigment, appearing slightly blue. In the elderly, fatty deposits on the sclera can make it appear slightly yellow. People with dark skin can have naturally darkened sclerae, the result of melanin pigmentation. The human eye is relatively rare for having a pale sclera (relative to the iris). This makes it easier for one individual to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Net
A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a condensation of neurons or, in more advanced forms, a central nervous system, organisms with radial symmetry are associated with nerve nets, and are found in members of the Ctenophora, Cnidaria, and Echinodermata phyla, all of which are found in marine environments. In the Xenacoelomorpha, a phylum of bilaterally symmetrical animals, members of the subphylum Xenoturbellida also possess a nerve net. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. It also exists in several other phyla, like chordates, annelids and flatworms, but then always alongside with longitudinal nerve(s) and/or a brain. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike central nervous systems, where neurons are typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excretion
Excretion is a process in which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell. Excretion is an essential process in all forms of life. For example, in mammals, urine is expelled through the urethra, which is part of the excretory system. In unicellular organisms, waste products are discharged directly through the surface of the cell. During life activities such as cellular respiration, several chemical reactions take place in the body. These are known as metabolism. These chemical reactions produce waste products such as carbon dioxide, water, salts, urea and uric acid. Accumulation of these wastes beyond a level inside the body is harmful to the body. The excretory organs remove these wastes. This process of removal of metabolic waste from the body is known as excretion. Green plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oesophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an Organ (anatomy), organ in vertebrates through which food passes, aided by Peristalsis, peristaltic contractions, from the Human pharynx, pharynx to the stomach. The esophagus is a :wiktionary:fibromuscular, fibromuscular tube, about long in adults, that travels behind the trachea and human heart, heart, passes through the Thoracic diaphragm, diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word ''oesophagus'' is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω (phérō, “I carry”) + ἔφαγον (éphagon, “I ate”). The wall of the esophagus from the Lumen (anatomy), lumen outwards consists of mucosa, submucosa (connective tissue), muscular layer, layers of mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non-homologous, differing in their origin, structure, function, and chemical composition. Human anatomy In human anatomy, "cuticle" can refer to several structures, but it is used in general parlance, and even by medical professionals, to refer to the thickened layer of skin surrounding fingernails and toenails (the eponychium), and to refer to the superficial layer of overlapping cells covering the hair shaft ( cuticula pili), consisting of dead cells, that locks the hair into its follicle. It can also be used as a synonym for the epidermis, the outer layer of skin. Cuticle of invertebrates In zoology, the invertebrate cuticle or cuticula is a multi-layered structure outside the epidermis of many invertebrates, notably roundworms and arthropods, in which it forms an exoskelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testis
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone, whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. Another method is to use cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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