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Bonytail Chub
The bonytail chub or bonytail (''Gila elegans'') is a cyprinid freshwater fish native to the Colorado River basin of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming in the southwestern United States; it has been extirpated from the part of the basin in Mexico. It was once abundant and widespread in the basin, its numbers and range have declined to the point where it has been listed as endangered since 1980 (ESA) and 1986 (IUCN), a fate shared by the other large Colorado basin endemic fish species like the Colorado pikeminnow, humpback chub, and razorback sucker. It is now the rarest of the endemic big-river fishes of the Colorado River. There are 20 species in the genus '' Gila'', seven of which are found in Arizona. Description A bonytail chub can grow to long. Like many other desert fishes, its coloring tends to be darker above and lighter below, serving as a camouflage. Breeding males have red fin bases. They have a streamlined body and a terminal mouth. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spencer Fullerton Baird
Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, Herpetology, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He eventually served as assistant Secretary of the Smithsonian from 1850 to 1878, and as Secretary from 1878 until 1887. He was dedicated to expanding the natural history collections of the Smithsonian which he increased from 6,000 specimens in 1850 to over 2 million by the time of his death. He published over 1,000 works during his lifetime. Early life and education Spencer Fullerton Baird was born in Reading, Pennsylvania in 1823. His mother was a member of the prominent Philadelphia Biddle family; he was a nephew of Speaker of the Pennsylvania Senate Charles B. Penrose and a first cousin, once removed, of U.S. Senator Boies Penrose and his distinguished brothers, R. A. F. Penrose Jr., Richard, Spencer Penrose, Spencer, and Charles Bingham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humpback Chub
The humpback chub (''Gila cypha'') is a federally protected fish that lived originally in fast waters of the Colorado River system in the United States. This species takes its name from the prominent hump between the head and dorsal fin, which is thought to direct the flow of water over the body and help maintain body position in the swift currents of the Colorado. The body is almost entirely scaleless, retaining only about 80 mid-lateral scales along the lateral line. The fish is very streamlined, with a thin caudal peduncle and a deeply forked tail. The back is a light olive gray, the sides silver, and the belly white. The dorsal fin usually has nine rays, and the anal fin 10 or more. Maximum recorded length is 38 cm. The humpback chub mostly consumes invertebrates and, to a lesser extent, other fish. They feed at all levels from the bottom to the surface. The species spawns from April through June, at water temperatures of 19-21 °C. The males develop nuptial tuberc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canyons
A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency to cut through underlying surfaces, eventually wearing away rock layers as sediments are removed downstream. A river bed will gradually reach a baseline elevation, which is the same elevation as the body of water into which the river drains. The processes of weathering and erosion will form canyons when the river's headwaters and estuary are at significantly different elevations, particularly through regions where softer rock layers are intermingled with harder layers more resistant to weathering. A canyon may also refer to a rift between two mountain peaks, such as those in ranges including the Rocky Mountains, the Alps, the Himalayas or the Andes. Usually, a river or stream carves out such splits between mountains. Examples of mountain-type c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quagga Mussel
The quagga mussel (''Dreissena rostriformis'', also known as ''Dreissena bugensis'' or ''Dreissena rostriformis bugensis'') is a species (or subspecies) of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae. It has an average lifespan of 3 to 5 years. The species is indigenous to the Dnieper River drainage of Ukraine, and is named after the quagga, an extinct subspecies of African zebra, possibly because, like the quagga, its stripes fade out towards the ventral side. The invasive quagga mussel is currently of major concern as it spreads in the rivers and lakes of Europe and also in the Great Lakes of North America where it was brought to by overseas shippers that use the Saint Lawrence Seaway. Appearance The quagga mussel shell is generally black, yellow, and/or zig-zagged. However, a large range of shell morphologies is seen, including a distinct morph in Lake Erie that is pale or completely white. The shell has a rounded carina and a convex ventral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Endangered Species
On 29 January 2010, the IUCN Red List of Threatened Species identified 5220 (2754 animals, 1 fungus, 2464 plant, 1 protist) endangered species, subspecies and varieties, stocks and sub-populations. For IUCN lists of endangered species by kingdom, see: *Animals (kingdom Animalia) — IUCN Red List endangered species (Animalia) **Amphibians — List of endangered amphibians **Birds — List of endangered birds **Fish — List of endangered fishes **Invertebrates — List of endangered invertebrates ***Arthropods — List of endangered arthropods ****Insects — List of endangered insects ***Molluscs List of endangered molluscs **Mammals — List of endangered mammals **Reptiles — List of endangered reptiles *Fungi (kingdom Fungi) — IUCN Red List endangered species (Fungi) *Plants (kingdom Plantae) — IUCN Red List endangered species (Plantae) *Protists (kingdom Protista) — IUCN Red List endangered species (Protista) References * IUCN 2009. IUCN Red List of Threatened ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green River (Colorado River)
The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of the U.S. states of Wyoming, Utah, and Colorado. The Green River is long, beginning in the Wind River Mountains of Wyoming and flowing through Wyoming and Utah for most of its course, except for a short segment of in western Colorado. Much of the route traverses the arid Colorado Plateau, where the river has carved some of the most spectacular canyons in the United States. The Green is slightly smaller than Colorado when the two rivers merge but typically carries a larger load of silt. The average yearly mean flow of the river at Green River, Utah is per second. The status of the Green River as a tributary of the Colorado River came about mainly for political reasons. In earlier nomenclature, the Colorado River began at its confluence with the Green River. Above the confluence, Colorado was called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoover Dam
Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives. It was referred to as Hoover Dam after President Herbert Hoover in bills passed by Congress during its construction; it was named Boulder Dam by the Roosevelt administration. The Hoover Dam name was restored by Congress in 1947. Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and produce hydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium named Six Companies, Inc., which began ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Hatchery
A fish hatchery is a place for artificial breeding, hatching, and rearing through the early life stages of animals—finfish and shellfish in particular.Crespi V., Coche A. (2008) Food and Agriculture Organization of the United Nations (FAO) Glossary of Aquacultur/ref> Hatcheries produce Fish larva, larval and juvenile fish, shellfish, and crustaceans, primarily to support the aquaculture industry where they are transferred to on-growing systems, such as fish farms, to reach harvest size. Some species that are commonly raised in hatcheries include Pacific oysters, shrimp, Indian prawns, salmon, tilapia and scallops. The value of global aquaculture farming is estimated to be US$98.4 billion in 2008 with China significantly dominating the market; however, the value of aquaculture hatchery and nursery production has yet to be estimated. Additional hatchery production for small-scale domestic uses, which is particularly prevalent in South-East Asia or for conservation programmes, ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functionally Extinct
Functional extinction is the extinction of a species or other taxon such that: #It disappears from the fossil record, or historic reports of its existence cease; #The reduced population no longer plays a significant role in ecosystem function; or #The population is no longer viable. There are no individuals able to reproduce, or the small population of breeding individuals will not be able to sustain itself due to inbreeding depression and genetic drift, which leads to a loss of fitness. In plant populations, self-incompatibility mechanisms may cause related plant specimens to be incompatible, which may lead to functional extinction if an entire population becomes self-incompatible. This does not occur in larger populations. In polygynous populations, where only a few males leave offspring, there is a much smaller reproducing population than if all viable males were considered. Furthermore, the successful males act as a genetic bottleneck, leading to more rapid genetic drift or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate, as well as making general aiming easier. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chameleons and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
