The bluegill is a species of freshwater fish sometimes referred to as bream, sunny, or copper nose. It is a member of the sunfish family Centrarchidae of the order Perciformes, it is native to North America and lives in streams, rivers and ponds. It is found east of the Rockies, it hides around, inside, old tree stumps and other underwater structures. It can live in either deep or shallow water, will move back and forth, depending on the time of day or season. Bluegills like to find shelter among water plants and in the shade of trees along banks. Bluegills can grow up to about 4 1⁄2 pounds, they have distinctive coloring, with deep blue and purple on the face and gill cover, dark olive-colored bands down the side, a fiery orange to yellow belly. The fish will eat anything they can fit in their mouth, they feed on small aquatic insects and fish. The fish play a key role in the food chain, are prey for muskies, trout, herons, snapping turtles, otters; the bluegill is the state fish of Illinois. The bluegill is noted for the black spot that it has on the posterior edge of the gills and base of the dorsal fin.
The sides of its head and chin are a dark shade of blue. It contains 5–9 vertical bars on the sides of its body, but these stripes are not always distinct, it has a yellowish abdomen, with the breast of the breeding male being a bright orange. The bluegill has three anal spines, ten to 12 anal fin rays, six to 13 dorsal fin spines, 11 to 12 dorsal rays, 12 to 13 pectoral rays, they are characterized by their flattened bodies. They have a terminal mouth, ctenoid scales, a lateral line, arched upward anteriorly; the bluegill ranges in size from about four to 12 inches, reaches a maximum size just over 16 inches. The largest bluegill caught was four pounds, 12 ounces in 1950; the bluegill is most related to the orangespotted sunfish and the redear sunfish, but different in a distinct spot at or near the base of the soft dorsal fin. The bluegill occurs in the United States east of the Rocky Mountains from coastal Virginia to Florida, west to Texas and northern Mexico, north to western Minnesota and western New York.
Today they have been introduced to everywhere else in North America, have been introduced into Europe, South Africa, Asia, South America, Oceania. Bluegills have been found in the Chesapeake Bay, indicating they can tolerate up to 1.8% salinity. In some locations where they have been transplanted, they are considered pests: trade in the species is prohibited in Germany and Japan. In the case of Japan, bluegills were presented to the then-crown prince, Akihito in 1960 as a gift by Richard J. Daley, mayor of Chicago; the prince, in turn, donated the fish to fishery research agencies in Japan from which they escaped, becoming an invasive species which has wreaked havoc with native species in Lake Biwa in Shiga Prefecture. The emperor has since apologized. Bluegill live in the shallow waters of many lakes and ponds, along with slow-moving areas of streams and small rivers, they prefer water with many aquatic plants, hide within fallen logs or water weeds. They can be found around weed beds, where they search for food or spawn.
In the summer, adults move to deep, open water where they suspend just below the surface and feed on plankton and other aquatic creatures. Bluegill try to spend most of their time in water from 60 to 80 °F, tend to have a home range of about 320 square feet during nonreproductive months, they enjoy heat, but do not like direct sunlight - they live in deeper water, but will linger near the water surface in the morning to stay warm. Bluegill are found in schools of 10 to 20 fish, these schools will include other panfish, such as crappie and smallmouth bass. Young bluegills' diet consists of rotifers and water fleas; the adult diet consists of aquatic insect larvae, but can include crayfish, leeches and other small fish. If food is scarce, bluegill will feed on aquatic vegetation, if scarce enough, will feed on their own eggs or offspring; as bluegill spend a great deal of time near the surface of water, they can feed on surface bugs. Most bluegills feed during daylight hours, with a feeding peak being observed in the morning and evening.
Feeding location tends to be a balance between predator abundance. Bluegill use gill bands of small teeth to ingest their food. During summer months, bluegills consume 3.2 percent of their body weight each day. To capture prey, bluegills use a suction system. Prey comes in with this water. Only a limited amount of water is able to be suctioned, so the fish must get within 1.75 centimeters of the prey. In turn, bluegill are prey to many larger species, including largemouth bass, smallmouth bass, muskellunge, northern pike, yellow perch, walleye and larger bluegill. Herons and otters have been witnessed catching bluegill in shallow water. However, the shape of the fish makes them hard to swallow. Bluegills have the ability to travel and change directions at high speeds by means of synchronized fin movements, they use notched caudal fins, soft dorsal fins, body undulations, pectoral fins to move forward. Having a notched caudal fin allows them to accelerate quickly; the speed of their forward motion depends on the strength of which they adduct fins.
The flat, slender body of
The lake whitefish is a species of freshwater whitefish from North America. Lake whitefish are found throughout much of Canada and parts of the northern United States, including all of the Great Lakes; the lake whitefish is sometimes referred to as a "humpback" fish due to the small size of the head in relation to the length of the body. It is a valuable commercial fish, occasionally taken by sport fishermen. Smoked, vacuum-packed lake whitefish fillets are available in North American grocery stores. Other vernacular names used for this fish include Otsego bass, Sault whitefish, gizzard fish, common whitefish, eastern whitefish, Great Lakes whitefish, humpback whitefish, inland whitefish and whitefish; the scientific genus name Coregonus means "angle eye" in Greek and the species name clupeaformis means "herring-shaped" in Latin. Lake whitefish are similar in appearance to other whitefishes in the Coregoninae subfamily of the salmon family Salmonidae, such as the northern cisco; as with all salmonids, they have an adipose fin.
To the distinction from cisco, the lake whitefish has a snout which overhangs the short lower jaw, so that the mouth opens in a inferior position. Thus the fish can feed on the bottom of lake beds or grab food particulates out of the water or from the surface of a water body; the cisco in turn has a short snout with a lower jaw. Both the cisco and lake whitefish are discernible from the mooneye due to the small posterior dorsal adipose fin. Another notable feature of the lake whitefish is the presence of two small flaps in each nostril, their coloration is silver to white with an olive to pale-green or brown dorsal hues. The ventral fins are white and the tail has a dark posterior edge; the tail fin of the lake whitefish is forked, making it a fast swimmer. Lake whitefish from inland lakes can reach a weight upwards of 5 pounds. On average, the lake whitefish weighs only 4 pounds, they can grow to 31 inches and reach 20 inches. Lake whitefish are cool water fish, they are found in a large number of inland lakes, they have been known to enter brackish waters.
The lake whitefish is distributed from Alaska and western Canada to the Atlantic coastal drainage of Maine and in New Brunswick north to Labrador. Lake whitefish spawn from September through January in water two to four metres in depth during the night. In the autumn, mature lake whitefish enter the shallows to lay their eggs on shoals of rubble and gravel. There is no parental care of the young. In the following spring the young will hatch. In northwestern Canada, a large spawning migration enters the Athabasca Delta in late summer, moving upstream in the Athabasca River; the longest single movement of a tagged whitefish recorded was 388 km, from Fort McMurray to the north shore of Lake Athabasca in Alberta, Canada. Fish of larval and postlarval stages feed on plankton. Once the larvae reach 3–4 inches they switch to feeding on bottom-dwelling animals which they will consume for the remainder of their lives. In late June and July, some inland lake populations of ciscoes and lake whitefish leave the deep, cool waters to feast on emerging mayflies and midges.
The lake whitefish's natural predators include burbot, lake trout, northern pike. Lake whitefish is one of the most important species for commercial inland fisheries in North America; the total annual catch in 1999 from Canada was 8 328 t and USA 5 353 t reported by the FAO. Lake whitefish is the prime commercial species of the upper Great Lakes fishery, because this delicately flavored fresh fish has high local consumer acceptance. An average of 11 million pounds was harvested from the Great Lakes annually from 1981-1999. Although the harvest has declined from 9.5 to 8 million pounds in recent years, prices have not increased. Instead, the price for Great Lakes lake whitefish, which once reached as high as $1.04/lb. Averages $.75/lb. and has dropped to as low as $.40/lb during periods of high production. Many amateur anglers enjoy hooking this fish in the months of June and early August. A simple line and jig system is enough to catch the fish as they feast on midges. In winter months, catching whitefish through the ice is popular in northern Wisconsin, with many fishing guides specializing in this species.
Successful icefishing techniques include using a jigging spoon, with at least one "slider hook" above and separated from the spoon with a barrel swivel, all hooks tipped with wax worms. Commercial fishing has allowed for the spread of this fish into many different markets and grocery store shelves. A major threat to the lake whitefish is the sea lamprey, it is one of a number of species aggressively attacked by sea lamprey. In Lake Michigan the sea lamprey began to decimate indigenous fish populations in the 1930s and 1940s, it may have entered the Great Lakes region through the Erie Canal which opened in 1825. and spread further in 1919 with improvements to the Welland Canal from Lake Ontario to Lake Erie, Lake Michigan, Lake Huron, Lake Superior. Since the end of the last glaciation, whitefish have re-colonized many North American lakes, from different directions, from refugia that represent genetically diverged stocks or races. After the invasions, the whitefish have diversified into dif
The goldeye is a freshwater fish found in Canada and the northern United States. It is one of only two remaining species in the family Hiodontidae, the other species being the mooneye; the species name alosoides means shad-like. It is called Winnipeg goldeye, western goldeye, yellow herring, toothed herring, shad mooneye, la Queche, weepicheesis, or laquaiche aux yeux d’or in French. Goldeyes are recognizable by their large gold eyes, their body appears to be a more white silver from below. They have two abdominal and pelvic fins as well as a dorsal on their back and an anal fin on their underside; the dorsal fin is positioned behind the origin of the anal fin. Goldeyes have a fleshy keel that extends from the pectoral fins to the base of the anal fin, their mouth is large and in the terminal position with a blunt round snout. The Goldeye fish has cycloid scales, they have a sensory system known as the lateral line system. Adults are about 15-17 inches but can reach 20 inches. Goldeyes weigh only 1-2 pounds.
The age of first reproduction for Goldeyes is 7 -- 10 years for 6 -- 9 years for males. They spawn in early June; the eggs that they lay are about 4 mm in size and they are semi-buoyant. This is more common in marine fish; the eggs are suspended to quiet waters. The majority of growth that occurs between June and September, it occurs from as far down the Mackenzie River as Aklavik in the north to Mississippi in the south, from Alberta in the west to Ohio south of the Great Lakes, with an isolated population south of James Bay. It prefers turbid slower-moving waters of rivers. Goldeyes feed on insects, fish, frogs; the fish averages less than 1 lb or 12 in in length, but can be found up to 2 lbs or 16 in in some lakes. It has been reported up to 52 cm in length; the goldeye is considered a good fly-fishing fish, but not popular with most anglers because of its small size. It is one of 122 new species of animals, fish documented by the Lewis & Clark Corps of Discovery. Commercial fishing of this species was reported as early as 1876.
Its fresh flesh is soft and unappealing, so it was only taken randomly in gillnets and sold for dogfood. They are now sought after by many consumers as a smoked fish. Many commercial fishermen sell them smoked after being processed in a brine made of spices, brown sugar, other secret ingredients, they are smoked in apple wood, or other woods. Each producer has their own ways of smoking. Despite its soft flesh the goldeye may be soaked in a salt brine for 24 hours and poached, firming up the flesh, its commercial viability was realized by Robert Firth, who immigrated to Winnipeg, Manitoba from Hull, England in 1886. Firth was carrying on a mediocre trade in cold-smoked goldeye, when he miscalculated the heat of his smoker and accidentally developed the now-standard method of hot-smoking it whole; the bright red or orange colour of the smoked fish resulted from using only willow smoke, but today is achieved through aniline dye. It became a fashionable gourmet dish after 1911, with Woodrow Wilson and the Prince of Wales counted amongst its fans.
In 1926–29 the annual catch exceeded a million pounds, but stocks declined from 1931 and little was fished from Lake Winnipeg after 1938. A small amount of the commercial harvest is shipped to the United States, but most is consumed in Canada. Although Lake Winnipeg was once the main commercial source, it now comes from elsewhere in Saskatchewan and Alberta, the culinary name Winnipeg goldeye has come to be associated with the city where it is processed; the fish is the namesake of the Winnipeg Goldeyes. List of smoked foods How to Smoke Goldeye Food portal McClane, A. J. "Goldeye", in McClane, A. J. McClane's New Standard Fishing Encyclopedia and International Angling Guide, New York: Holt and Winston, ISBN 0-03-060325-0 Murray, L. “Goldeye” in the Canadian Encyclopedia Scott, W. B.. J. Freshwater Fishes of Canada, Ottawa: Fisheries Research Board of Canada, pp. 327–332, ISBN 0-660-10239-0 Goldeye in Fisheries and Oceans Canada's Underwater World "Hiodon alosoides". Integrated Taxonomic Information System.
Retrieved 24 January 2006. Froese and Pauly, eds.. "Hiodon alosoides" in FishBase. August 2005 version
The golden redhorse, Moxostoma erythrurum, is a species of freshwater fish endemic to Ontario and Manitoba in Canada and the Midwestern and eastern United States. It lives in calm silty or sandy waters in streams, small to large rivers, lakes. A bottom-feeder, it feeds on microcrustaceans, aquatic insects, detritus and small mollusks; the golden redhorse spawns in the spring. The golden redhorse can be found in freshwater habitats across 25 different states in the eastern half of North America. There are populations located in the drainage basins of the Mississippi River, Ohio River, the lower Missouri River; the fish can be found in the Great Lakes, excluding Lake Superior, the Lakes’ basin, as well as in the Lake of the Woods. The Mobile Bay drainage basin in the states of Alabama and southeastern Tennessee contains the golden redhorse. In Mississippi there is an isolated population in the southwestern part of the state; some suspect that it is a relict population, meaning the range of the fish was once much larger than it is today.
They were introduced into the Potomac River in Maryland and West Virginia, but the date of this introduction is unknown. A golden redhorse was seen in this river in 1953, but was never seen there again until 1971. In Canada, the golden redhorse is endemic to Ontario; the fish can be found in the Red River of the North, a river which empties into Hudson Bay. Coincidentally, the Red River in Texas houses the golden redhorse. Golden redhorses average around 12-18 inches long and weigh between 1-2 pounds, although some can reach up to 26 inches and 4-5 pounds; the golden scales decorating its sides gave the fish its name. They have olive colored backs, white bellies, slate gray tail fins, their body is fusiform in shape, allowing them to fight against currents in streams to capture their prey. The mouth of the fish is in the inferior position; the dorsal fin is concave and the caudal fin is notched. It paired pelvic and pectoral fins; the pelvic fins are in the abdominal position, while the pectoral fins are located in more of a thoracic position.
It has a lateral line system consisting of 39 to 42 scales, used to detect movement and vibrations in the surrounding water. Golden redhorses can be found in freshwater streams and rivers with varied substrates. In pools they are found over sand and silt, they have been seen living in lakes or larger reservoirs that are fed by a stream or river. Compared to other redhorse species the golden redhorse is not sensitive to poor environmental conditions; the diet of the golden redhorse consists of a variety of aquatic creatures. They consume larval insects, small mollusks and other aquatic invertebrates. Like most other members of the sucker family, Catostomidae and algae are staples of the golden redhorse's diet, it is a bottom-feeding species, able to use its protrusible mouth to suck up food objects from the stream bed. The golden redhorse lives for 8–11 years and becomes sexually mature at age 3-5, they spawn in the spring once water temperatures are between 17-22 °C. When this occurs depends on the geographic location, but spawning happens at night during April or May.
Spawning most occurs in a runs or riffles within the main stream, but some individuals may move into smaller, more well protected tributaries. The spawning streams are gravel bottomed, as their benthic, bottom-dwelling young prefer to hide beneath the stones after they hatch from their adhesive eggs. Golden redhorses provide no parental care to their offspring; the young form large schools and feed together along the stream bottom. Some schools may include a mixture of different redhorse species; the golden redhorse is a game fish, but it is a species not pursued by anglers. It is caught by accident when anglers fish on the bottom for catfish. Fishing for members of the sucker family occurs in the early spring when the water temperature reaches 42 °F. Fishing several inches off the stream bottom with simple worms as bait is a good method to catch suckers. Gigging for suckers is another common practice; this is done using a multi-headed spear at night with a mounted light on the bow of the boat. The golden redhorse can be cooked pickled.
NatureServe - Moxostoma erythrurum
The white sucker is a freshwater cypriniform fish inhabiting the upper Midwest and Northeast in North America, but is found as far south as Georgia and New Mexico in the south and west. The fish is known as a "sucker" due to its fleshy, papillose lips that suck up organic matter and aufwuchs from the bottom of rivers and streams. Other common names for the white sucker include bay fish, brook sucker, common sucker, mullet; the white sucker is confused with the longnose sucker, because they look similar. The white sucker is a long, round-bodied fish with a dark green, copper, brown, or black back and sides and a light underbelly; the fish has typical features of primitive Cypriniformes fishes, such as a homocercal tail, cycloid scales, dorsal and pelvic fin rays. When full grown, it can weigh 2 to 6 pounds; the fish's suckermouth with its fleshy lips are located in the inferior position at the bottom of its head, as the fish obtains its food from bottom surfaces. These fish are commonly mistaken for different types of suckers and redhorse, but can be distinguished by the complete lateral line system containing 55-85 small scales.
Since the fish is adaptable to different habitats and changing environmental influences. However, white suckers are found in small streams and lakes in the Midwest and East Coast of the United States; the white sucker is relatively tolerant of turbid and polluted waters. The white sucker is a bottom feeder, meaning that it uses its fleshy lips to suck up bottom sediments and other organisms that may be located there, it will eat anything it can, but most small invertebrates and plant matter. Larger predatory fish species such as walleye, bass, northern pike, catfish and sauger prey on the white sucker; the white sucker spawns in shallow water or streams in April and May. Two or more males may gather with one female, which releases up to 10,000 eggs that can be fertilized by the gathered males. A common fish, the white sucker is not fished for food, though some consider it good to eat, it is most used as bait. When it is eaten by humans, it is processed and sold under the name of mullet. Fossils of this fish in the United States occur as early as the Early Pleistocene.
Froese and Pauly, eds.. "Catostomus commersonii" in FishBase. 06 2006 version. "Hybrid'Muttsucker' Has Genes Of Three Species". Science Daily. Aug 15, 2008. Retrieved 2008-08-15. Species profile by Earl J. S. Rook Wisconsin Sea Grant Fish of the Great Lakes species profile Nova Scotia Department of Agriculture and Fisheries factsheet World Register of Marine Species entry
The yellow perch referred to as perch, is a freshwater perciform fish native to much of North America. The yellow perch was described in 1814 by Samuel Latham Mitchill from New York, it is related, morphologically similar to the European perch. Other common names for yellow perch include American perch, lake perch, raccoon perch, ring-tail perch, ringed perch, striped perch. Another nickname for the perch is the Dodd fish. Latitudinal variability in age, growth rates, size have been observed among populations of yellow perch resulting from differences in day length and annual water temperatures. In many populations, yellow perch live 9 to 10 years, with adults ranging from 4 to 10 in in length; the world record yellow perch was caught in 1865 in New Jersey, is the longest-standing record for freshwater fish in North America. The yellow perch has a yellow and brass-colored body and distinct pattern, consisting of five to nine olive-green, vertical bars, triangular in shape, on each side, its fins are lighter with an orange hue on the margins.
The body is laterally compressed. The anterior portion of the body is deep tapering into a slender caudal peduncle; the opercle is scaled, a single spine is present on the posterior margin. As with all percid fishes, yellow perch have two dorsal fins; the anterior consists of 11 -- 15 spines. The posterior dorsal fin has a straight margin, consisting of 12 -- 16 rays; the nape and belly of yellow perch are all scaled. A complete lateral line is present; the anal fin consists of six to nine rays. A single spine and five rays make up the pelvic fins, the pectoral fins consist of 13–15 rays; the caudal fin of the yellow perch is forked. Yellow perch are only found in North America. In Canada, its native range extends throughout Nova Quebec north to the Mackenzie River, it is common in the northwest to Great Slave Lake and west into Alberta. It is not native to any other areas of Canada. In the United States, the native range extends south into Ohio and Illinois, throughout most of the northeastern United States.
It is considered native to the Atlantic Slope basin, extending south to the Savannah River. The yellow perch has been introduced for sport and commercial fishing purposes, it has been introduced to establish a forage base for bass and walleye. These introductions were predominantly performed by the U. S. Fish Commission in the late 19th and early 20th centuries. However, unauthorized introductions have occurred from illegal introductions, dispersal through connected waterways, use as live bait. Isolated populations now occur in southwest portions of the United States; the yellow perch has not been introduced outside of North America. Introductions in Canada have been less intense than in the United States. Yellow perch reach sexual maturity in 2–3 years for males and 3–4 years for females, they are iteroparous, spawning annually in the spring when water temperatures are between 2.0 and 18.6 °C. Spawning is communal and occurs at night. Yellow perch are oviparous. Eggs are laid in a gelatinous strand, a characteristic unique among North American freshwater fishes.
Egg strands are draped over weeds, the branches of submerged trees or shrubs, or some other structure. Eggs hatch in 11–27 days, depending on temperature and other abiotic factors, they are found in the littoral zones of both large and small lakes, but they inhabit slow-moving rivers and streams, brackish waters, ponds. Yellow perch reside in shallow water, but are found deeper than 15 m or on the bottom. In the northern waters, perch tend to grow at a slower rate. Females in general are larger, grow faster, live longer, mature in 3-4 years compared to males, which mature in 2-3 years at a smaller size. Most research has showed the maximum age to be about 9–10 years, with a few living past 11 years; the preferred temperature range for the yellow perch is 17 to 25 °C, with an optimum range of 21 to 24 °C and a lethal limit in upwards of 33 °C and a stress limit over 26 °C. Yellow perch spawn once a year in spring using large schools and shallow areas of a lake or low-current tributary streams, they do not build a nest.
Spawning takes place at night or in the early morning. Females have the potential to spawn up to eight times in their lifetimes. A small aquaculture industry in the US Midwest contributes about 90,800 kg of yellow perch annually, but the aquaculture is not expanding rapidly; the yellow perch is crucial to the survival of the walleye and largemouth bass in its range. Cormorants feed on yellow perch in early spring, but over the entire season, only 10% of their diets is perch. Cormorants and anglers combined harvest 40% of 1- and 2-year-old yellow perch and 25% of the adult yellow perch population in Lake Michigan. Total annual mortality of adult yellow perch has not changed since cormorant colonization. Yellow perch is recognized by its dark vertical stripes and gold or yellow body color. Perca is derived from early Greek for "perch" and flavescens is Latin for "becoming gold" or "yellow colored". Adult sizes range from 3.9–11.4 in (10–30
A lake is an area filled with water, localized in a basin, surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, therefore are distinct from lagoons, are larger and deeper than ponds, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which are flowing. Most lakes streams. Natural lakes are found in mountainous areas, rift zones, areas with ongoing glaciation. Other lakes are found along the courses of mature rivers. In some parts of the world there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will fill in with sediments or spill out of the basin containing them. Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic, recreational purposes, or other activities.
The word lake comes from Middle English lake, from Old English lacu, from Proto-Germanic *lakō, from the Proto-Indo-European root *leǵ-. Cognates include Dutch laak, Middle Low German lāke as in: de:Wolfslake, de:Butterlake, German Lache, Icelandic lækur. Related are the English words leak and leach. There is considerable uncertainty about defining the difference between lakes and ponds, no current internationally accepted definition of either term across scientific disciplines or political boundaries exists. For example, limnologists have defined lakes as water bodies which are a larger version of a pond, which can have wave action on the shoreline or where wind-induced turbulence plays a major role in mixing the water column. None of these definitions excludes ponds and all are difficult to measure. For this reason, simple size-based definitions are used to separate ponds and lakes. Definitions for lake range in minimum sizes for a body of water from 2 hectares to 8 hectares. Charles Elton, one of the founders of ecology, regarded lakes as waterbodies of 40 hectares or more.
The term lake is used to describe a feature such as Lake Eyre, a dry basin most of the time but may become filled under seasonal conditions of heavy rainfall. In common usage, many lakes bear names ending with the word pond, a lesser number of names ending with lake are in quasi-technical fact, ponds. One textbook illustrates this point with the following: "In Newfoundland, for example every lake is called a pond, whereas in Wisconsin every pond is called a lake."One hydrology book proposes to define the term "lake" as a body of water with the following five characteristics: it or fills one or several basins connected by straits has the same water level in all parts it does not have regular intrusion of seawater a considerable portion of the sediment suspended in the water is captured by the basins the area measured at the mean water level exceeds an arbitrarily chosen threshold With the exception of the seawater intrusion criterion, the others have been accepted or elaborated upon by other hydrology publications.
The majority of lakes on Earth are freshwater, most lie in the Northern Hemisphere at higher latitudes. Canada, with a deranged drainage system has an estimated 31,752 lakes larger than 3 square kilometres and an unknown total number of lakes, but is estimated to be at least 2 million. Finland has larger, of which 56,000 are large. Most lakes have at least one natural outflow in the form of a river or stream, which maintain a lake's average level by allowing the drainage of excess water; some lakes do not have a natural outflow and lose water by evaporation or underground seepage or both. They are termed endorheic lakes. Many lakes are artificial and are constructed for hydro-electric power generation, aesthetic purposes, recreational purposes, industrial use, agricultural use or domestic water supply. Evidence of extraterrestrial lakes exists. Globally, lakes are outnumbered by ponds: of an estimated 304 million standing water bodies worldwide, 91% are 1 hectare or less in area. Small lakes are much more numerous than large lakes: in terms of area, one-third of the world's standing water is represented by lakes and ponds of 10 hectares or less.
However, large lakes account for much of the area of standing water with 122 large lakes of 1,000 square kilometres or more representing about 29% of the total global area of standing inland water. Hutchinson in 1957 published a monograph, regarded as a landmark discussion and classification of all major lake types, their origin, morphometric characteristics, distribution; as summarized and discussed by these researchers, Hutchinson presented in it a comprehensive analysis of the origin of lakes and proposed what is a accepted classification of lakes according to their origin. This