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Cavernicola (worm)
Cavernicola is a suborder of planarians found mostly in freshwater habitats of caves, although some species occur on the surface. Description The main morphological feature that defines the suborder Cavernicola is the placement of their ovaries. They are located more posteriorly than in other planarians, which usually have them close to the brain. The reproductive system of planarians, copulatory apparatus has a copulatory bursa in most species, although in some it is absent and is replaced by a connection to the intestine. Taxonomy The suborder Cavernicola was originally erected for the family Dimarcusidae due to its unusual morphological features that did not match those of the other planarian suborders. Recently, the discovery of another unusual cave species led to the erection of a new family, Amphibioplanidae, which as also included in Cavernicola due to shared morphological features. References {{Taxonbar, from=Q21616179 Cavernicola (worm) Protostome suborde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hausera Hauseri
''Hausera'' is a subterranean genus of Tricladida, planarian from Brazil. It contains only the single species ''Hausera hauseri''. It is the first cave-dwelling member of the suborder Cavernicola (worm), Cavernicola to have been observed in South America. Etymology Both the genus and species were named after Josef Hauser (zoologist), Josef Hauser, a researcher of freshwater flatworms. Description Specimens are long and wide. The Pharynx#Invertebrates, pharynx is long, and along with the gonopore is located in the hindmost third of the body. While it lacks eyes, the head has a pair of ciliated sensory organs approximately 140 micrometre, μm back from the body's anterior end. The intestine extends into the brain and connects with the reproductive system via a genito-intestinal duct. The testicular follicles are arranged in uneven rows near the margins of the body, and the ovaries are located behind but in proximity to the brain, approximately 0.6 millimeters behind the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimarcusidae
Dimarcusidae is a family of triclads found mostly in freshwater habitats of caves, although at least one species, '' Rhodax evelinae'', occurs in surface waters. Currently the family contains only seven species distributed in five genera, although the total number of species is thought to be much higher. Description The morphological features uniting species of Dimarcusidae are related to the reproductive system. Their ovaries are located more posteriorly than in most triclads, which usually have them close to the brain. The penis in species of Dimarcusidae contains glandular elements and the common ovovitelline duct is perpendicular to the female genital duct. Taxonomy The family Dimarcusidae was erected in 1972 by Mitchell and Kawakatsu to include a new species, ''Dimarcus villalobosi''. However, the same species had been briefly described by Benazzi in the same year as '' Opisthobursa mexicana'' and this name had priority, with ''Dimarcus villalobosi'' becoming a junior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suborder
Order () 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 follow consistent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planarian
Planarians (triclads) are free-living flatworms of the class Turbellaria, order Tricladida, which includes hundreds of species, found in freshwater, marine, and terrestrial habitats.pp 3., "Planarians (the popular name for the group as a whole), or triclad flatworms (the more scientific designation of the same group), are acoelomate bilaterians". Planarians are characterized by a three-branched intestine, including a single anterior and two posterior branches. Their body is populated by adult stem cells called neoblasts, which planarians use for regenerating missing body parts. Many species are able to regenerate any missing organ, which has made planarians a popular model in research of regeneration and stem cell biology. The genome sequences of several species are available, as are tools for molecular biology analysis. The order Tricladida is split into three suborders, according to their phylogenetic relationships: Maricola, Cavernicola and Continenticola. Formerly, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave
Caves or caverns are natural voids under the Earth's Planetary surface, surface. Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance underground (such as rock shelters). Caves which extend further underground than the opening is wide are called endogene caves. Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called Caving, ''caving'', ''potholing'', or ''spelunking''. Formation types The formation and development of caves is known as ''speleogenesis''; it can occur over the course of millions of years. Caves can range widely in size, and are formed by various geological processes. These may involve a combination of chemical processes, erosion by water, tectonic forces, microorganisms, pressure, and atmospheric influences. Isotopic dating techniques can be applied to cave sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive System Of Planarians
The reproductive system of planarians is broadly similar among different families, although the associated structures can vary in complexity. All planarians are hermaphrodites, so their reproductive system has a male and a female part. Both parts communicate with the surface of the body via a single opening called gonopore, which is located on the ventral side of the posterior half of the body. Male part of the reproductive system The male part of the reproductive system in planarians has a set of several testicles, distributed throughout the body in two or more rows. They are usually concentrated in the anterior two thirds of the body, although they can reach close to the posterior end. The testicles are connected to a pair of sperm ducts which run posteriorly towards the gonopore. In some groups, the sperm ducts met in their Distal#Proximal and distal 2, distal part, forming the ejaculatory duct, which then opens in a cavity called “male atrium”. In others, like land ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavernicola (worm)
Cavernicola is a suborder of planarians found mostly in freshwater habitats of caves, although some species occur on the surface. Description The main morphological feature that defines the suborder Cavernicola is the placement of their ovaries. They are located more posteriorly than in other planarians, which usually have them close to the brain. The reproductive system of planarians, copulatory apparatus has a copulatory bursa in most species, although in some it is absent and is replaced by a connection to the intestine. Taxonomy The suborder Cavernicola was originally erected for the family Dimarcusidae due to its unusual morphological features that did not match those of the other planarian suborders. Recently, the discovery of another unusual cave species led to the erection of a new family, Amphibioplanidae, which as also included in Cavernicola due to shared morphological features. References {{Taxonbar, from=Q21616179 Cavernicola (worm) Protostome suborde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
