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Splitfin
Goodeidae is a family of teleost fish endemic to Mexico and some areas of the United States. Many species are known as splitfins. This family contains about 50 species within 18 genera. The family is named after ichthyologist George Brown Goode (1851-1896). Distribution The family is divided into two subfamilies, the Goodeinae and the Empetrichthyinae. The Goodeinae are endemic to shallow freshwater habitats in Mexico, particularly along the Mesa Central area (especially the Lerma River basin, smaller rivers directly south of it and inland to around the Valley of Mexico region), with some species found in brackish fringes at the Pacific coast, and north to central Durango, central Sinaloa and north San Luis Potosí. There are about 45 species of Goodeinae in 16 genera (some list 2 additional genera). The Empetrichthyinae are found in the southwestern Great Basin in Nevada, the United States, and contains 4 species in 2 genera. Physical information The name "splitfin" co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redtail Splitfin
The redtail splitfin or redtail goodeid (''Xenotoca eiseni'') is a species of goodeid fish from the family Goodeidae and subfamily Goodeinae. Like other members of Goodeinae, the redtail splitfin is native to Mexico and a livebearer. However, the goodeid mating system differs in several ways from the more common livebearing fish from the family Poeciliidae that includes guppies and swordtails. While no goodeid species is a very popular aquarium fish, the redtail splitfin is one of the most popular. Only the male has the red-orange tail for which it is named. Its specific name honours the collector of the type, Gustav Eisen (1847–1940) who was Curator of Marine Invertebrates at the California Academy of Sciences in San Francisco, California. Range and habitat The redtail splitfin comes from west-central Mexico in the Grande de Santiago River basin and waters near Compostela, Nayarit. It might also occur in the uppermost Ameca and Armería River basins, but the taxonom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinaloa
Sinaloa (), officially the Estado Libre y Soberano de Sinaloa ( en, Free and Sovereign State of Sinaloa), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. It is divided into Municipalities of Sinaloa, 18 municipalities and its capital city is Culiacán, Culiacán Rosales. It is located in Northwestern Mexico, and is bordered by the states of Sonora to the north, Chihuahua (state), Chihuahua and Durango to the east (separated from them by the Sierra Madre Occidental) and Nayarit to the south. To the west, Sinaloa faces Baja California Sur across the Gulf of California. The state covers an area of , and includes the Islands of Palmito Verde, Palmito de la Virgen, Altamura, Santa María, Saliaca, Macapule and San Ignacio. In addition to the capital city, the state's important cities include Mazatlán and Los Mochis. History Sinaloa belongs to the northern limit of Mesoamerica. From the Fuerte River ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fisheries
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both in freshwater waterbodies (about 10% of all catch) and the oceans (about 90%). About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem — causing declines in some populations. Because of their economic and social importance, fisheries are governed by complex fisheries management practices and legal regimes that vary widely across countries. Historically, fisheries were treated with a " first-come, first-served " approach, but recent threats by human overfishing and environmental issues have required increased regulation of fisheries to prevent conflict and increase profitable economic activity on the fishery. Modern jurisdicti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. Industry Desiccation is widely employed in the oil and gas industry. These materials are obtained in a hydrated state, but the water content leads to corrosion or is incompatible with downstream processing. Removal of water is achieved by cryogenic condensation, absorption into glycols, and absorption onto desiccants such as silica gel. Laboratory A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry. The material is placed on a shelf, and a drying agent or ''desiccant'', such as dry silica gel or anhydrous sodium hydroxide, is placed below the shelf. Often some sort of humidity indicator is included in the desiccator to show, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplankton productivity". Water bodies with very low nutrient levels are termed oligotrophic and those with moderate nutrient levels are termed mesotrophic. Advanced eutrophication may also be referred to as dystrophic and hypertrophic conditions. Eutrophication can affect freshwater or salt water systems. In freshwater ecosystems it is almost always caused by excess phosphorus. In coastal waters on the other hand, the main contributing nutrient is more likely to be nitrogen, or nitrogen and phosphorus together. This depends on the location and other factors. When occurring naturally, eutrophication is a very slow process in which nutrients, especially phosphorus compounds and organic matter, accumulate in water bodies. These nutrients deriv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Although environmental pollution can be caused by natural events, the word pollution generally implies that the contaminants have an anthropogenic source – that is, a source created by human activities. Pollution is often classed as point source or nonpoint source pollution. In 2015, pollution killed nine million people worldwide (one in six deaths). This remained unchanged in 2019, with little real progress against pollution being identifiable. Air pollution accounted for of these earlier deaths. Major forms of pollution include air pollution, light pollution, litter, noise pollution, plastic pollution, soil contamination, radioactiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Impact On The Environment
Human impact on the environment (or anthropogenic impact) refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society is causing severe effects including global warming, environmental degradation (such as ocean acidification), mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Some human activities that cause damage (either directly or indirectly) to the environment on a global scale include population growth, overconsumption, overexploitation, pollution, and deforestation. Some of the problems, including global warming and biodiversity loss, have been proposed as representing catastrophic risks to the survival of the human species. The term ''anthropogenic'' designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian geologist Alexey Pavlov, and it w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copulation (zoology)
In zoology, copulation is animal sexual behavior in which a male introduces sperm into the female's body, especially directly into her reproductive tract. This is an aspect of mating. Many animals that live in water use external fertilization, whereas internal fertilization may have developed from a need to maintain gametes in a liquid medium in the Late Ordovician epoch. Internal fertilization with many vertebrates (such as all reptiles, some fish, and most bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...s) occurs via cloacal copulation, known as cloacal kiss (see also hemipenis), while mammals copulate vaginally, and many primitive (biology), basal vertebrates reproduce sexually with external fertilization. In spiders and insects Spiders are often confused with insects, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrotrophy
Matrotrophy is a form of maternal care during organism development, associated with live birth (viviparity), in which the embryo of an animal or flowering plant is supplied with additional nutrition from the mother (e.g. through a placenta). This can be contrasted with lecithotrophy, in which the only source of nutrition for the embryo is yolk originally contained within its egg. Vegetal matrotrophy In plants, matrotrophy is considered a critical evolutionary development preceding the origin of embryophytes and therefore essential to the evolution of land plants. Matrotrophy is facilitated by cytological and ultrastructural modifications on one or both sides of the generational junction, a region called the placenta. Specialization of the placental cells pertains further to their cytological and ultrastructural characteristics: the cytoplasm is often dense and rich in lipids, the vacuole is typically reduced but large in ''Sphagnum'', the endoplasmic reticulum extensive, mitochon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andropodium
Fins are distinctive anatomical features composed of bony spine (zoology), spines or Ray (fish fin anatomy), rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper (anatomy), flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the Vertebral column, spine and are supported only by muscles. Their principal function is to help the fish aquatic locomotion, swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Fertilisation
Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For internal fertilization to happen there needs to be a method for the male to introduce the sperm into the female's reproductive tract. Most taxa that reproduce by internal fertilization are gonochoric. In mammals, reptiles, and certain other groups of animals, this is done by copulation, an intromittent organ being introduced into the vagina or cloaca. In most birds, the cloacal kiss is used, the two animals pressing their cloacas together while transferring sperm. Salamanders, spiders, some insects and some molluscs undertake internal fertilization by transferring a spermatophore, a bundle of sperm, from the male to the female. Following fertilization, the embryos are laid as eggs in oviparous organisms, or continue to develop inside th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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