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Cavefish
Cavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, troglomorphic fish, troglobitic fish, stygobitic fish, phreatic fish and hypogean fish.Romero, Aldemaro, editor (2001). ''The Biology of Hypogean Fishes.'' Developments in Environmental Biology of Fishes. Helfman, G.S. (2007). ''Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources'', pp. 41–42. Island Press. There are more than 200 scientifically described species of obligate cavefish found on all continents, except Antarctica. Although widespread as a group, many cavefish species have very small ranges and are seriously threatened.Fenolio, D.B.; Zhao, Y.; Niemiller, M.L.; and Stout, J. (2013). ''In-situ observations of seven enigmatic cave loaches and one cave barbel from Guangxi, China, with notes on conservation status.'' Speleobiology Notes 5: 19-33. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexican Tetra
The Mexican tetra (''Astyanax mexicanus''), also known as the blind cave fish, blind cave characin, and blind cave tetra, is a freshwater fish of the family Characidae of the order Characiformes. The type species of its genus, it is native to the Nearctic realm, originating in the lower Rio Grande and the Neueces and Pecos Rivers in Texas, as well as the central and eastern parts of Mexico. Growing to a maximum total length of , the Mexican tetra is of typical characin shape, with unremarkable, drab coloration. Its blind cave form, however, is notable for having no eyes or pigment; it has a pinkish-white color to its body (resembling an albino). This fish, especially the blind variant, is reasonably popular among aquarists. ''A. mexicanus'' is a peaceful species that spends most of its time in midlevel water above the rocky and sandy bottoms of pools and backwaters of creeks and rivers of its native environment. Coming from a subtropical climate, it prefers water with 6.5&nd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stygobitic
Stygofauna are any fauna that live in groundwater systems or aquifers, such as caves, fissures and vugs. Stygofauna and troglofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments – stygofauna are associated with water, and troglofauna with caves and spaces above the water table. Stygofauna can live within freshwater aquifers and within the pore spaces of limestone, calcrete or laterite, whilst larger animals can be found in cave waters and wells. Stygofaunal animals, like troglofauna, are divided into three groups based on their life history - stygophiles, stygoxenes, and stygobites. # Stygophiles inhabit both surface and subterranean aquatic environments, but are not necessarily restricted to either. # Stygoxenes are like stygophiles, except they are defined as accidental or occasional presence in subterranean waters. Stygophiles and stygoxenes may live for part of their lives in caves, but don't complete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyprinidae - Phreatichthys Andruzzii
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest vertebrate animal family in general with about 3,000 species, of which only 1,270 remain extant, divided into about 370 genera. Cyprinids range from about 12 mm in size to the giant barb (''Catlocarpio siamensis''). By genus and species count, the family makes up more than two-thirds of the ostariophysian order Cypriniformes. The family name is derived from the Greek word ( 'carp'). Biology and ecology Cyprinids are stomachless fish with toothless jaws. Even so, food can be effectively chewed by the gill rakers of the specialized last gill bow. These pharyngeal teeth allow the fish to make chewing motions against a chewing plate formed by a bony process of the skull. The pharyngeal teeth are unique to each species and are used by s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congo Blind Barb
''Caecobarbus geertsi'', the African blind barb or Congo blind barb (known as ''Nzonzi a mpofo'' in the local Kikongo language, meaning "blind barb"), is a species of cyprinid fish. This threatened cavefish is only known from Democratic Republic of the Congo, and it is the only member of the monotypic genus ''Caecobarbus''. George Albert Boulenger described this fish in 1921 and it apparently lacks any close relatives in the Congo region. Despite its common name, "African blind barb", other blind cave cyprinids are indigenous to Africa, notably the Somalian '' Barbopsis devecchi'' and '' Phreatichthys andruzzii''. Range The Congo blind barb is found only in the Thysville Cave system, a part of the lower Congo River basin (notably Kwilu and Inkisi tributaries) in the Democratic Republic of the Congo. The area where found covers about , and is located at an altitude around above sea level. It was initially known from seven caves in the Thysville system and an additional seve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typhleotris Madgascarensis
''Typhleotris madagascariensis'' is a species of fish in the family Milyeringidae that is endemic to Madagascar, where it is only known from underground waters in the southwestern portion of the island. This cavefish is blind and lacks pigmentation, and can reach a standard length of . This species is known from more than 10 caves and sinkholes in the Mahafaly Plateau region, in places where the water temperature typically ranges from and the pH is slightly above neutral. Although considered endangered because of its restricted range and not found to be common anywhere in its range in earlier studies, recent surveys found that the species is locally abundant, occurring in especially high numbers in the Andranoilove, Andriamaniloke, Lalia and Mitoho caves. In the southern part of its range, ''T. madagascariensis'' co-occurs with '' T. mararybe'', which is not as common or widespread. ''T. madagascariensis'' feeds on various invertebrates. Some of the limestone caves where th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Fish
A blind fish is a fish without functional eyes. Most blind fish species are found in dark habitats such as the deep ocean, deep river channels and underground. Blind fish species Agnathans *'' Myxine glutinosa'' *''Myxine circifrons'' *'' Polistotrema stouti'' Cartilaginous fishes *Torpediniformes **'' Benthobatis moresbyi'' **'' Typhlonarke aysoni'' **'' Typhlonarke tarakea'' Bony fishes * Anguilliformes ** Moringuidae ***'' Moringua abbreviata'' *Salmoniformes ** Ipnopidae ***'' Ipnops murrayi'' ***'' Ipnops agassizi'' ***'' Ipnops meadi'' ***'' Bathymicrops regis'' ***'' Bathymicrops brevianalis'' ***'' Bathyphlops sewelli'' *Characiformes ** Characidae ***'' Anoptichthys jordani'' ***'' Anoptichthys hubbsi'' ***'' Anoptichthys antrobius'' ***'' Stygichthys typhlops'' * Cypriniformes ** Cyprinidae ***'' Caecobarbus geertsii'' ***'' Barbopsis devecchii'' ***'' Iranocypris typhlops'' ***'' Phreatichthys andruzzii'' ***'' Typhlogarra widdowsoni'' ***' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troglobitic
A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live underground (eutroglophiles), and species that are only cave visitors ( subtroglophiles and trogloxenes). Land-dwelling troglobites may be referred to as troglofauna, while aquatic species may be called stygofauna, although for these animals the term ''stygobite'' is preferable. Troglobites typically have evolutionary adaptations to cave life. Examples of such adaptations include slow metabolism, reduced energy consumption, better food usage efficiency, decrease or loss of eyesight (anophthalmia), and depigmentation (absence of pigment in the integument). Conversely, as opposed to lost or reduced functions, many species have evolved elongated antenna and locomotory appendages, in order to better move around and respond to environmental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea caves, rock shelters, and grottos, that extend a relatively short distance into the rock and they are called ''exogene'' caves. 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'', ''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, microorgani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photophobia (biology)
In biology, photophobia (adjective: photophobic) is negative response to light. Photophobia is a behavior demonstrated by insects or other animals which seek to stay out of the light. In botany, the term photophobia/photophobic describes shade-loving plants that thrive in low light conditions. Photophobia (or photophobic response) may also refer to a negative phototaxis Phototaxis is a kind of taxis, or locomotory movement, that occurs when a whole organism moves towards or away from a stimulus of light. This is advantageous for phototrophic organisms as they can orient themselves most efficiently to receive ... or phototropism response. References Physiology {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adapted
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by change in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that interlock with those of the othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pineal Eye
A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhythmicity and hormone production for thermoregulation. The hole in the head which contains the eye is known as a pineal foramen or parietal foramen, since it is often enclosed by the parietal bones. Presence in various animals The parietal eye is found in the tuatara, most lizards, frogs, salamanders, certain bony fish, sharks, and lampreys. It is absent in mammals, but was present in their closest extinct relatives, the therapsids, suggesting it was lost during the course of the mammalian evolution due to it being useless in endothermic animals. It is also absent in the ancestrally endothermic ("warm-blooded") archosaurs such as birds. The parietal eye is also lost in ectothermic ("cold-blooded") archosaurs like crocodilians, and in turtles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pineal Gland
The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep patterns in both circadian and seasonal cycles. The shape of the gland resembles a pine cone, which gives it its name. The pineal gland is located in the epithalamus, near the center of the brain, between the two hemispheres, tucked in a groove where the two halves of the thalamus join. The pineal gland is one of the neuroendocrine secretory circumventricular organs in which capillaries are mostly permeable to solutes in the blood. Nearly all vertebrate species possess a pineal gland. The most important exception is a primitive vertebrate, the hagfish. Even in the hagfish, however, there may be a "pineal equivalent" structure in the dorsal diencephalon. The lancelet '' Branchiostoma lanceolatum'', an early chordate which is a close relative to vertebrates, also lacks a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
