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Ribeiroia Congolensis
''Ribeiroia'' () is a genus of trematode parasites that sequentially infect freshwater snails in the family Planorbidae (ramshorn snails) as first intermediate Host (biology), hosts, fish and larval amphibians as second intermediate hosts, and birds and mammals as definitive hosts (see ). In North America, infection by ''Ribeiroia'' has been linked to amphibians with limb Birth defect, malformations. The connection between Parasitic disease, parasitic infection and limb malformations has generated questions about (a) whether parasite-induced malformations in amphibians are increasing (see ), and (b) the consequences of such abnormalities for amphibian population conservation (see ). Taxonomy ''Ribeiroia'' is a genus of parasites in the class Trematoda, phylum Flatworm, Platyhelminthes. Currently three species and one subspecies of ''Ribeiroia'' are recognized: ''Ribeiroia ondatrae, R. ondatrae'' in North America, ''R. marini'' in the Caribbean, ''R. m. guadeloupensis'' on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lauro Travassos
Lauro Pereira Travassos (2 July 1890 – 20 November 1970) was a Brazilian parasitologist. He collected helminth specimens from across South America and studied their life-histories. He built a Brazilian school of parasitology through his students. His son Lauro Pereira Travassos Filho (1918–1989) became an entomologist while another son Haroldo Pereira Travassos, Haroldo Pereira became an ichthyologist. Travassos was born in Angra dos Reis. He studied medicine at Rio de Janeiro and his first work was on ''Linguatula serrata'' in the intestine of a patient. His doctoral thesis was on species of Heterakidae, Heterakinae. He then worked at the Oswaldo Cruz Foundation, Instituto Oswaldo Cruz which was then called the Manguinhos under José Gomes de Faria. He became chair of parasitology at the faculty of medicine in São Paulo in 1926. In 1929 he went to the tropical institute of Hamburg to work with the helminthologist Friedrich Fülleborn (1866–1933). He became a full professor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematoda
Trematoda is a class of flatworms known as trematodes, and commonly 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 a mollusk, usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five 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. The etymology of trematode stems from the Greek word ''trēmatṓdēs'', which means "pierced with holes", and refers to the worm's sucker, which pierces a hole in the host while the worm is attached and feeding. Taxonomy There are 18,000 to 24,000 known species of trematodes, divided into two subclasses — the Aspidogastrea and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miracidia
The miracidium is the second stage in the life cycle of trematodes. When trematode eggs are laid and come into contact with fresh water, they hatch and release miracidium. In this phase, miracidia are ciliated and free-swimming. This stage is completed upon coming in contact with, and entering into, a suitable intermediate host for the purposes of asexual reproduction. Many different species of ''Trematoda'' exist, expressing some variation in the physiology and appearance of the miracidia. The various trematode species implement similar strategies to increase their chances of locating and colonizing a new host. Anatomy ''Hirudinella ventricosa'' The trematode '' Hirudinella ventricosa'' releases eggs in strings. Each egg contains a single miracidium, while the string contains living spermatozoa. Miracidia have cilia that are only present in the upper portion of the body near an apical gland with 12 hook-like spines in the opening. ''Echinostoma paraensei'' Miracidia usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. In placental mammals, sperm cells exit the penis through the male urethra and enter the vagina during copulation, while egg cells enter the uterus through the oviduct. Other vertebrates of both sexes possess a cloaca for the release of sperm or egg cells. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Life Cycle
In biology, a biological life cycle (or just life cycle when the biological context is clear) is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then itself goes through the same series of stages, the process repeating in a cyclic fashion. "The concept is closely related to those of the life history, Developmental biology, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction. In some organisms, different "generations" of the species succeed each other during the life cycle. For Embryophyte, plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetics
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinostoma
''Echinostoma'' is a genus of Trematoda, trematodes (flukes), which can infect both humans and other animals. These intestinal trematoda, flukes have a three-host life cycle with snails or other aquatic organisms as intermediate hosts, and a variety of animals, including humans, as their host (biology), definitive hosts. ''Echinostoma'' infect the human gastrointestinal tract, gastrointestinal tract of humans, and can cause a disease known as echinostomiasis. The parasites are spread when humans or animals eat infected raw or undercooked food, such as bivalvia, bivalve molluscs or fish. Taxonomy There has been debate about the number of species in this group, with estimates as high as 120 unique species of ''Echinostoma'', however, currently 16 species have been accepted as valid species with another 10 to be validated ''Echinostoma'' are difficult to biological classification, classify based on morphology alone. Many species look alike and can be considered cryptic species com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladocystis Trifolium
Opisthorchiidae is a family of digenean trematodes. Opisthorchiidae have cosmopolitan distribution. The most medically important species in the family Opisthorchiidae are ''Clonorchis sinensis'', ''Opisthorchis viverrini'', and '' Opisthorchis felineus'', that are causes of the disease clonorchiasis. Some species are parasites of economically important fish, e.g. ''Clarias gariepinus''.Jansen van Rensburg, C., van As, J.G. & King, P.H. 2013. New records of digenean parasites of ''Clarias gariepinus'' (Pisces: Clariidae) from the Okavango Delta, Botswana, with description of ''Thaparotrema botswanensis'' sp. n. (Plathelminthes: Trematoda). ''African Invertebrates ''African Invertebrates'' is a peer-reviewed open access scientific journal that covers the taxonomy, systematics, biogeography, ecology, conservation, and palaeontology of Afrotropical invertebrates, whether terrestrial, freshwater, or marine. A ...'' 54 (2): 431–446. Subfamilies Thirteen subfamilies are in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esophagus
The esophagus (American English), oesophagus (British English), or œsophagus (Œ, archaic spelling) (American and British English spelling differences#ae and oe, see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), colloquially known also as the food pipe, food tube, 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 ''esophagus'' is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω (phérō, "I carry") + ἔφαγον ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology (from Ancient Greek μορφή (morphḗ) "form", and λόγος (lógos) "word, study, research") is the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, color, pattern, size), as well as the form and structure of internal parts like bones and organs, i.e., anatomy. This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of the overall structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Fried ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequencing
In genetics and biochemistry, sequencing means to determine the primary structure (sometimes incorrectly called the primary sequence) of an unbranched biopolymer. Sequencing results in a symbolic linear depiction known as a sequence which succinctly summarizes much of the atomic-level structure of the sequenced molecule. DNA sequencing DNA sequencing is the process of determining the nucleotide order of a given DNA fragment. So far, most DNA sequencing has been performed using the chain termination method developed by Frederick Sanger. This technique uses sequence-specific termination of a DNA synthesis reaction using modified nucleotide substrates. However, new sequencing technologies such as pyrosequencing are gaining an increasing share of the sequencing market. More genome data are now being produced by pyrosequencing than Sanger DNA sequencing. Pyrosequencing has enabled rapid genome sequencing. Bacterial genomes can be sequenced in a single run with several times cov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
