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Coitocaecum Parvum
''Coitocaecum parvum'' is a digeneic trematode or flatworm (Platyhelminthes) that is parasitic to the intestine of the common bully ('' Gobiomorphus cotidianus'') or upland bully (''G. breviceps''). The common and upland bully are freshwater fish of New Zealand that ''C. parvum'' uses as its definitive host. ''C. parvum'' is a hermaphroditic freshwater trematode that can omit its definitive host and produce eggs by selfing or progenesis inside its amphipod second intermediate host (Lagrue et al., 2001) Life cycle The life cycle of ''C. parvum'' begins when eggs are released into the water and hatch into free-swimming miracidia. The miracidia then penetrate the first intermediate host, ''Potamopyrgus antipodarum'' (the New Zealand mud snail), where they multiply and develop into sporocysts. Next, free-living cercariae are asexually produced from the sporocysts and shed by the snails. These shed cercarial larvae then penetrate the hemocoel The blood circulatory syste ... [...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 vermifo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can also reproduce asexually. While all prokaryotes reproduce without the formation and fusion of gametes, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphallus
''Microphallus'' is a genus of parasitic trematodes (flukes) in the family Microphallidae. The Greek name means "tiny penis". Hosts They are parasitic on a variety of molluscs, crustaceans, birds, and mammals, some species having complex life cycles involving more than one host. For example, '' Microphallus piriformes'' parasitizes the rough periwinkle (''Littorina saxatilis''); when these are eaten by herring gulls it infects the bird and lays its eggs in the bird's feces to infect new periwinkles. Other intermediate hosts include, for example New Zealand mud snail ''Potamopyrgus antipodarum'' and others. Parasite-host interactions Several species are notable for manipulating or influencing their hosts. '' Microphallus piriformes'' causes its host, the rough periwinkle, to move upwards, making it more vulnerable to predation by herring gulls. '' Microphallus pseudopygmaeus'' chemically castrates (parasitic castration) its host, the snail '' Onoba aculeus'', and causes it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progenesis
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared to other primates. In progenesis or paedogenesis, sexual development is accelerated. Both neoteny and progenesis result in paedomorphism (as having the form typical of children) or paedomorphosis (changing towards forms typical of children), a type of heterochrony. It is the retention in adults of traits previously seen only in the young. Such retention is important in evolutionary biology, domestication and evolutionary developmental biology. Some authors define paedomorphism as the retention of larval traits, as seen in salamanders.Schell, S. C. ''Handbook of Trematodes of North America North of Mexico'', 1985, pg. 22 History and etymology The origins of the concept of neoteny have been traced to the Bible (as argued by Ashley Montag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metacercariae
Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions. The life cycle of a typical trematode begins with an egg. Some trematode eggs hatch directly in the environment (water), while others are eaten and hatched within a host, typically a mollusc. The hatchling is called a ''miracidium,'' a free-swimming, ciliated larva. Miracidia will then grow and develop within the intermediate host into a sac-like structure known as a sporocyst or into rediae, either of which may give rise to free-swimming, motile cercariae larvae. The cercariae then could either infect a vertebrate host or a second intermediate host. Adult metacercariae or mesocercariae, depending on the individual trematode's life cycle, will then infect the vertebrate host or be rejected and excreted thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracalliope Fluviatilis
''Paracalliope fluviatilis'' is a species of amphipod in the family Paracalliopiidae Paracalliopiidae is a family of amphipods, containing the following genera: *'' Doowia'' Barnard & Drummond, 1987 *'' Indocalliope'' Barnard & Karaman, 1982 *'' Katacalliope'' Barnard & Drummond, 1984 *'' Paracalliope'' Stebbing, 1899 *''Yhi In .... References Gammaridea Articles created by Qbugbot Crustaceans described in 1879 {{amphipod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemocoel
The blood circulatory system is a organ system, system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek ''kardia'' meaning ''heart'', and from Latin ''vascula'' meaning ''vessels''). The circulatory system has two divisions, a systemic circulation, systemic circulation or circuit, and a pulmonary circulation, pulmonary circulation or circuit. Some sources use the terms ''cardiovascular system'' and ''vascular system'' interchangeably with the ''circulatory system''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The Closed circulatory system, circulatory system is closed in vertebrates, which means that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larvae
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles, adults are immobil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cercaria
A cercaria (plural cercariae) is the larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. A cercaria has a tapering head with large penetration glands. It may or may not have a long swimming "tail", depending on the species. The motile cercaria finds and settles in a host where it will become either an adult, or a mesocercaria, or a metacercaria, according to species. Rotifers (''Rotaria Rotaria is a genus of asexual, microscopic animal known as a bdelloid rotifer. Analysis published in 2007 of morphology and DNA sequence data of species form the genus confirmed that despite their asexual mechanism of reproduction, two fundame ... rotatoria'') produce a chemical, Schistosome Paralysis Factor, suppressing cercaria swimming and reducing infections.{{cite journal , editor1-last=Khosla , editor1-first=Chaitan , last1=Gao, first1=Jiarong, last2=Yang, first2=Ning, last3=Lewis, first3=Fred A., last4=Yau, first4=Peter, la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematode
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 — ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematode Lifecycle Stages
Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions. The life cycle of a typical trematode begins with an egg. Some trematode eggs hatch directly in the environment (water), while others are eaten and hatched within a host, typically a mollusc. The hatchling is called a ''miracidium,'' a free-swimming, ciliated larva. Miracidia will then grow and develop within the intermediate host into a sac-like structure known as a sporocyst or into rediae, either of which may give rise to free-swimming, motile cercariae larvae. The cercariae then could either infect a vertebrate host or a second intermediate host. Adult metacercariae or mesocercariae, depending on the individual trematode's life cycle, will then infect the vertebrate host or be rejected and excreted thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamopyrgus Antipodarum
The New Zealand mud snail (''Potamopyrgus antipodarum'') is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae. It is native to New Zealand, where it is found throughout the country, but it has been introduced to many other countries, where it is often considered an invasive species because populations of the snail can reach very high densities. Shell description The shell of ''Potamopyrgus antipodarum'' is elongated and has dextral coiling, with 7 to 8 whorls. Between whorls are deep grooves. Shell colors vary from gray and dark brown to light brown. The average height of the shell is approximately 5 mm (\begin \frac \end in); maximum size is approximately 12 mm (\begin \frac \end in). The snail is usually 4–6 mm in length in the Great Lakes, but grows to 12 mm in its native range. It is an operculate snail, with a 'lid' that can seal the opening of its shell. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
