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Entosphenus Tridentatus
The Pacific lamprey (''Entosphenus tridentatus'') is an anadromous parasitic lamprey from the Pacific Coast of North America and Asia. It is a member of the Petromyzontidae family. The Pacific lamprey is also known as the three-tooth lamprey and tridentate lamprey. Description Pacific lampreys grow to about as adults. They are anadromous and semelparous. They have slender, elongated bodies with two dorsal fins arising far back on the body. The anal fins are rudimentary and the lower lobe of the caudal fin is larger than the upper lobe and both lobes are continuous with the dorsal fin and the anal fin. Adults living in the sea are a bluish-black or greenish colour above and pale below, but those in fresh water are brown. This species is distinguished by having three (or occasionally two) sharp teeth on the supraoral bar above the mouth and three sharp points on each lateral plate. The Pacific lamprey are often found at sea or often far offshore. At sea, depth: near surface to 1, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Richardson (naturalist)
Sir John Richardson Royal Society of London, FRS FRSE (5 November 1787 – 5 June 1865) was a Scotland, Scottish naval surgeon, natural history, naturalist and Arctic explorer. Life Richardson was born at Nith Place in Dumfries the son of Gabriel Richardson, Provost of Dumfries, and his wife, Anne Mundell. He was educated at Dumfries Grammar School. He was then apprenticed to his maternal uncle, Dr James Mundell, a surgeon in Dumfries. He studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of 1819–1822. Richardson wrote the sections on geology, botany and ichthyology for the official account of the expedition. Franklin and Richardson returned to Canada in 1825 and went overland by fur trade routes to the mouth of the Mackenzie River. Franklin was to go as far west as possible and Richardson was to go east to the mouth of the Coppermine River. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilisation
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Processes such as insemination or pollination which happen before the fusion of gametes are also sometimes informally called fertilisation. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In Antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of interaction between the female's ovum and male's sperm to form a zygote in frog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snagging
Snagging, also known as snag fishing, snatching, snatch fishing, jagging (Australia), or foul hooking, is a fishing technique for catching fish that uses sharp grappling hooks tethered to a fishing line to externally pierce (i.e. "snag") into the flesh of nearby fish, without needing the fish to swallow any hook with its mouth like in angling. This is achieved by suddenly and vigorously pulling the line (either by handlining or with a rod) when movement is felt, causing the snag hook to "claw" into any fish unfortunate enough to be grappled by the hook points. Weighted multi-hook rigs can be used to increase chances of success, and modern technologies such as underwater video camera can also be used to visually aid and time the snagging. Some herbivorous/ algaevorous fish species, such as paddlefish, are not attracted to normal angling baits or lures as they primarily filter-feed on plankton. While these fish can be caught using nets, spears or pole hooks, snagging is also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willamette River
The Willamette River ( ) is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is long, lying entirely in northwestern Oregon in the United States. Flowing northward between the Oregon Coast Range and the Cascade Range, the river and its tributaries form the Willamette Valley, a basin that contains two-thirds of Oregon's population, including the state capital, Salem, and the state's largest city, Portland, which surrounds the Willamette's mouth at the Columbia. Originally created by plate tectonics about 35 million years ago and subsequently altered by volcanism and erosion, the river's drainage basin was significantly modified by the Missoula Floods at the end of the most recent ice age. Humans began living in the watershed over 10,000 years ago. There were once many tribal villages along the lower river and in the area around its mouth on the Columbia. Indigenous peoples lived throughout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willamette Falls
The Willamette Falls is a natural waterfall on the Willamette River between Oregon City and West Linn, Oregon, in the United States. It is the largest waterfall in the Northwestern United States by volume, and the seventeenth widest in the world. Horseshoe in shape, it is wide and high with a flow of 30,849 cu ft/s (874 m³/s), located upriver from the Willamette's mouth. Willamette Falls is a culturally significant site for many tribal communities in the region. Opened in 1873 and closed since 2011, the Willamette Falls Locks allowed boat traffic on the Willamette to pass into the main Willamette Valley. Human history Native American oral history taught that the falls were placed there by the ancient hero T'allapus (Coyote) so that their people would have fish to eat all winter.· Willamette Falls was once the home to the Charcowah village of the Clowewalla band of Tumwaters or Willamette Band of Tumwaters, an upper Chinookan speaking people. These lands were ceded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Hydroelectric Dams On The Columbia River
There are more than 60 dams in the Columbia River watershed in the United States and Canada. Tributaries of the Columbia River and their dammed tributaries, as well as the main stem itself, each have their own list below. The dams are listed in the order as they are found from source to terminus. Many of the dams in the Columbia River watershed were not created for the specific purposes of reservoir, water storage or flood protection. Instead, the primary purpose of many of these dams is to produce hydroelectricity. As can be seen in the lists, these dams provide many tens of gigawatts of power. Major dam construction began in the early 20th century and picked up the pace after the Columbia River Treaty in the 1960s, by the mid 1980s all the big dams were finished. Including just the dams listed below, there are 60 dams in the watershed, with 14 on the Columbia, 20 on the Snake River, Snake, seven on the Kootenay River, Kootenay, seven on the Pend Oreille River, Pend Oreill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eel River (California)
The Eel River (Wiyot: ''Wiya't''; Cahto: ''Taanchow''; Northern Pomo: ''ch'idiyu'') is a major river, about long, of northwestern California. The river and its tributaries form the third largest watershed entirely in California, draining a rugged area of in five counties. The river flows generally northward through the Coast Ranges west of the Sacramento Valley, emptying into the Pacific Ocean about downstream from Fortuna and just south of Humboldt Bay. The river provides groundwater recharge, recreation, and industrial, agricultural and municipal water supply.William M. Brown and John R. RitterSediment transport and Turbidity in the Eel River Basin, 1971, prepared in cooperation with the California Department of Water Resources, 67 pages The Eel River system is among the most dynamic in California because of the region's unstable geology and the influence of major Pacific storms. The discharge is highly variable; average flows in January and February are over 100 times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wiyot People
The Wiyot (Wiyot language, Wiyot: Wíyot, Tolowa language, Chetco-Tolowa: Wee-’at xee-she or Wee-yan’ Xee-she’, Tututni language, Euchre Creek Tututni: Wii-yat-dv-ne - "Mad River People“, Yurok language, Yurok: Weyet) are an indigenous people of California living near Humboldt Bay, California and a small surrounding area. They are culturally similar to the Yurok people (Wiyot term: ''Hiktok''). They called themselves simply Ku'wil, meaning "the People". Today, there are approximately 450 Wiyot people. They are enrolled in several federally recognized tribes, such as the Wiyot Tribe (also known as the Table Bluff Reservation—Wiyot Tribe), Bear River Band of the Rohnerville Rancheria, Blue Lake Rancheria, and the Cher-Ae Heights Indian Community of the Trinidad Rancheria."Wiyot Indians." ''SDSU: California Indians and Their Res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klamath River
The Klamath River (Karuk: ''Ishkêesh'', Klamath: ''Koke'', Yurok: ''Hehlkeek 'We-Roy'') flows through Oregon and northern California in the United States, emptying into the Pacific Ocean. By average discharge, the Klamath is the second largest river in California after the Sacramento River. It drains an extensive watershed of almost that stretches from the arid country of south-central Oregon to the temperate rainforest of the Pacific coast. Unlike most rivers, the Klamath begins in the high desert and flows toward the mountains – carving its way through the rugged Cascade Range and Klamath Mountains before reaching the sea. The upper basin, today used for farming and ranching, once contained vast freshwater marshes that provided habitat for abundant wildlife, including millions of migratory birds. Most of the lower basin remains wild, with much of it designated wilderness. The watershed is known for this peculiar geography, and the Klamath has been called "a river upsid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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