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Lemon Tetra
The lemon tetra (''Hyphessobrycon pulchripinnis'') is a species of tropical freshwater fish which originates from South America, belonging to the family Characidae. It is a small tetra growing to 5 cm in length. The species is a long established favourite aquarium fish, being introduced to the aquarium in 1932. Description The lemon tetra is one of the deeper-bodied tetras, contrasting with slender, torpedo-shaped relations such as the cardinal tetra and the rummy nosed tetra, whose approximate body shape when seen from the side is that of a lozenge,(often referred to as a diamond, is a form of rhombus). The basic body color of an adult specimen is a translucent yellow, with a pearlescent lustre emanating from the scales in particularly fine specimens. The dorsal and anal fin of the fish are marked with black and yellow: specifically, the anal fin is hyaline (glass-like appearance), with a black outer margin, the anterior three or four rays being an intense, acrylic lemon-y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Ahl
Christoph Gustav Ernst Ahl (1 September 1898 – 14 February 1945) was a German Zoology, zoologist, born in Berlin. He was the director of the department of ichthyology and herpetology in the Museum für Naturkunde. He was also the editor in chief of the review ''Das Aquarium'' from 1927 to 1934. During World War II, Ahl fought in the ranks of the Wehrmacht - in Poland, North Africa and later Yugoslavia. He was executed while in refuge in Yugoslavia, after the partisans found out he was a German. He performed one of the first studies on Pogona, bearded dragons determining what genus they belong to. Ahl is commemorated in the scientific names of two species of lizards: ''Anolis ahli'' and ''Emoia ahli''.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . ("Ahl", p. 3). The latter is a synonym of ''Emoia battersbyi''. See also *:Taxa named by Ernst Ahl References Further rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otocinclus
''Otocinclus'' is a genus of catfish in the family Loricariidae native to South America, commonly known as "dwarf suckers" or "otos". This genus, like other loricariids, is characterized by rows of armour plating covering the body, as well as the underslung suckermouth. They are generally small in size; ''O. tapirape'' is the smallest of the species (2.4 cm), while ''O. flexilis'' is the biggest (5.5 cm). These species have adaptations that allow them to breathe air. A duct forms at the junction between the esophagus and the stomach and expands into an enlarged, ring-like diverticulum, characteristic of this genus, which allows air-breathing.Armbruster, J.W. (1998)Modifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid Catfishes.''Copeia, 1998 (3): 663–675.'' ''Otocinclus'' are popular aquarium fish, and they are often purchased as algae eaters. It is difficult to breed them in captivity, and only wild caught ''Otocinclus'' are available to h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Ernst Ahl
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Described In 1937
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Most fis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Fish
Tropical fish are generally those fish found in aquatic tropical environments around the world. Fishkeepers often keep tropical fish in freshwater and saltwater aquariums. The term "tropical fish" is not a taxonomic group, but rather is a general term for fish found in such environments, particularly those kept in aquariums. Aquarium fish Tropical fish is a term commonly used to refer to fish that are kept in heated aquariums. Freshwater tropical fish are more commonly kept than saltwater tropical fish due to the common availability of fresh water sources, such as tap water, whereas salt water is not commonly available and has to be recreated by using fresh water with sea salt additions. Salt water has to be monitored to maintain the correct salinity because of the effects of evaporation. Freshwater tropical aquariums can be maintained by simply topping up with fresh water. Tropical fish are popular choices for aquariums due to their often bright coloration, which typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetras
Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by government agencies, emergency services, (police forces, fire departments, ambulance) for public safety networks, rail transport staff for train radios, transport services and the military. TETRA is the European version of trunked radio, similar to Project 25. TETRA is a European Telecommunications Standards Institute (ETSI) standard, first version published 1995; it is mentioned by the European Radiocommunications Committee (ERC). Description TETRA uses time-division multiple access (TDMA) with four user channels on one radio carrier and 25 kHz spacing between carriers. Both point-to-point and point-to-multipoint transfer can be used. Digital data transmission is also included in the standard though at a low data rate. TETRA Mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Freshwater Aquarium Fish Species
A vast number of aquatic species have successfully adapted to live in the freshwater aquarium. This list gives some examples of the most common species found in home aquariums. Catfish Characins and other characiformes Cichlids Cyprinids Loaches and related cypriniformes Live-bearers and killifish Labyrinth fish Rainbowfish Gobies and sleepers Sunfish and relatives Other fish See also * List of aquarium fish by scientific name *List of brackish aquarium fish species *List of fish common names * List of freshwater aquarium amphibian species *List of freshwater aquarium invertebrate species *List of freshwater aquarium plant species * List of marine aquarium fish species * List of marine aquarium invertebrate species * The Aquarium Wiki Encyclopaedia List of Freshwater aquarium fish Sources * Encyclopedia of Aquarium and Pond Fish (2005) ( David Alderton) * 500 Aquari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg (biology)
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods such as insects, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was in size. Whale shark eggs typically hatch within the mother. At and up to , the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubifex
''Tubifex'' is a cosmopolitan genus of tubificid annelids that inhabits the sediments of lakes, rivers and occasionally sewer lines. At least 13 species of ''Tubifex'' have been identified, with the exact number not certain, as the species are not easily distinguishable from each other. Reproduction ''Tubifex'' worms are hermaphroditic: each individual has both male (testes) and female (ovaries) organs in the same animals. These minute reproductive organs are attached to the ventral side of the body wall in the celomic cavity. In mature specimens, the reproductive organs are clearly found on the ventral side of the body. Copulation and cocoon formation Although the ''Tubifex'' worms are hermaphrodites, the male and female organs become mature at different times; thus self-fertilization is avoided, and cross-fertilization is encouraged. Two mature ''Tubifex'' worms undergo copulation by joining ventral and anterior surfaces together with their anterior ends pointing opposite d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chironomidae
The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species superficially resemble mosquitoes, but they lack the wing scales and elongated mouthparts of the Culicidae. The name Chironomidae stems from the Ancient Greek word ''kheironómos'', "a pantomimist". Common names and biodiversity This is a large taxon of insects; some estimates of the species numbers suggest well over 10,000 world-wide. Males are easily recognized by their plumose antennae. Adults are known by a variety of vague and inconsistent common names, largely by confusion with other insects. For example, chironomids are known as "lake flies" in parts of Canada and Lake Winnebago, Wisconsin, but "bay flies" in the areas near the bay of Green Bay, Wisconsin. They are called "sand flies", "muckleheads", "muffleheads", "Canadian so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daphnia
''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resembles the movements of fleas. ''Daphnia'' spp. live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds. The two most commonly found species of ''Daphnia'' are '' D. pulex'' (small and most common) and '' D. magna'' (large). They are often associated with a related genus in the order Cladocera: ''Moina'', which is in the Moinidae family instead of the Daphniidae, and is much smaller than ''D. pulex'' (roughly half the maximum length). Appearance and characteristics The body of a ''Daphnia'' species is usually long, and is divided into segments, although this division is not visible. The head is fused, and is generally bent down towards the body with a visible notch separating the two. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeration
Aeration (also called aerification or aeriation) is the Systems engineering process, process by which air is circulated through, mixed with or solvation, dissolved in a liquid or other substances that act as a fluid (such as soil). Aeration processes create additional surface area in the mixture, allowing greater chemical or suspension reactions. Aeration of liquids Methods Aeration of liquids (usually water) is achieved by: * passing air through the liquid by means of the Venturi tube, Aeration Turbine, aeration turbines or compressed air which can be combined with diffuser(s) air stone(s), as well as fine bubble diffusers, coarse bubble diffusers or linear aeration tubing. Ceramics are suitable for this purpose, often involving dispersion of fine air or gas bubbles through the porous ceramic into a liquid. The smaller the bubbles, the more gas is exposed to the liquid increasing the gas transfer efficiency. Diffusers or spargers can also be designed into the system to cause turbu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
