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Rugogastridae
Rugogastridae is a family of trematodes in the order Aspidogastrida. It consists of a single genus, ''Rugogaster'' Schell, 1973. Species *'' Rugogaster callorhinci'' Amato & Pereira, 1995Amato, J. & Pereira, J., Jr. (1995). A new species of ''Rugogaster'' (Aspidobothrea: Rugogastridae) parasite of the elephant fish, ''Callorhinchus callorhynchi'' (Callorhinchidae), from the estuary of the La Plata River, Coasts of Uruguay and Argentina. ''Revista Brasileira de Parasitologia Veterinária'', 4(1), 1–7. *'' Rugogaster hydrolagi'' Schell, 1973 Morphological characteristics Species of ''Rugogaster'' are parasitic in the rectal glands of various holocephalan fishes. They are characterized by a row of rugae, numerous testes 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 testostero ..., and two c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspidogastrida
Aspidogastrida is an Order (biology), order of Trematoda, trematodes in the Class (biology)#Hierarchy of ranks, subclass Aspidogastrea. Families *Superfamily Aspidogastrioidea Poche, 1907Poche, F. (1907). Einige Bemerkungen zur Nomenklatur der Trematoden. ''Zoologischer Anzeiger'', 31, 124-126. **Aspidogastridae Poche, 1907 **Multicalycidae Gibson & Chinabut, 1984Gibson, D. & Chinabut, S. (1984). ''Rohdella siamensis'' gen. et sp. nov. (Aspidogastridae: Rohdellinae subfam. nov.) from fresh water fishes in Thailand, with a reorganization of the classification of the subclass Aspidogastrea. ''Parasitology'', 88(3), 383–393. **Rugogastridae Schell, 1973Schell, S. C. (1973). ''Rugogaster hydrolagi'' gen. et sp. n. (Tremtoda: Aspidobothrea: Rugogastridae fam. n.) from the ratfish ''Hydrolagus collei'' (Lay & Bennett, 1839). ''The Journal of Parasitology'', 59, 803–805. References Further reading *Alves, P., Vieira, F., Santos, C., Scholz, T. & Luque, J. (2015). A checklist o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspidogastrea
The Aspidogastrea (Ancient Greek: ' “shield”, ' “stomach/pouch”) is a small group of flukes comprising about 80 species. It is a subclass of the trematoda, and sister group to the Digenea. Species range in length from approximately one millimeter to several centimeters. They are parasites of freshwater and marine molluscs and vertebrates (cartilaginous and bony fishes and turtles). Maturation may occur in the mollusc or vertebrate host. None of the species has any economic importance, but the group is of very great interest to biologists because it has several characters which appear to be archaic. Morphology Shared characteristics Shared characteristics of the group are a large ventral disc with a large number of small alveoli ("suckerlets") or a row of suckers and a tegument with short protrusions, so-called "microtubercles". Larval physiology Larvae of some species have ciliated patches. Those of ''Multicotyle purvisi'' have four patches on the anterior side of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematoda
Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish. Etymology Trematodes are commonly referred to as flukes. This term can be traced back to the Old English name for flounder, and refers to the flattened, rhomboidal shape of the organisms. Taxonomy There are 18,000 to 24,000 known species of trematodes, divided into two subclasses — the Aspidogastrea and the Digenea. Aspidogastrea is the smaller subclass, comprising 61 species. These flukes mainly infect bivalves and bony fishes.https://www.biotaxa.org/Zootaxa/article/view/zootaxa.3918.3.2 Digenea — which comprise the majority of trematodes — are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order (biology)
Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. 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 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocephali
Holocephali ("complete heads"), sometimes given the term Euchondrocephali, is a subclass of cartilaginous fish in the class Chondrichthyes. The earliest fossils are of teeth and come from the Devonian period. Little is known about these primitive forms, and the only surviving group in the subclass is the order Chimaeriformes. Chimaeriformes, commonly known as chimaeras, includes the rat fishes in the genus '' Chimaera'', and the elephant fishes in the genus '' Callorhinchus''. These fishes move by using sweeping movements of their large pectoral fins. They are deep sea fish with slender tails, living close to the seabed to feed on benthic invertebrates. They lack a stomach, their food moving directly into the intestine. Extinct holocephalans were much more diverse in lifestyles, including shark-like predatory forms and slow, durophagous fish. Characteristics Members of this taxon preserve today some features of elasmobranch life in Paleozoic times, though in other respects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruga
Ruga may refer to: * Ruga (anatomy), an anatomical fold *Ruga, Nepal * Ruga language, an extinct Sino-Tibetan language that was spoken in Meghalaya, India *Ruga-Ruga Ruga-Ruga (sometimes called Rugaruga) were irregular troops in Eastern Africa, often deployed by western colonial forces.Karl WeuleRugaruga in: Heinrich Schnee (Hrsg.); '' Deutsches Koloniallexikon''. Band III, Berlin: Quelle & Meyer, 1920, S. 19 ..., irregular troops in Eastern Africa, often deployed by western colonial forces * Rugila, 5th-century Hunnic ruler * Spurius Carvilius Ruga, 3rd-century Roman grammarian who invented the letter ''g'' {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testes
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 calip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
