|
Grayling Zone
The classification of European rivers comes from the fish fauna found in them. Changes in taxonomic composition relate to physical and chemical changes that occur longitudinally. Zonation (from headwater to estuary) Trout zone This zone has a characteristic steep gradient, fast flowing water and cool temperature. The fast flow rate causes turbulence which keeps the water well oxygenated. Fish species found in this zone usually lay adhesive eggs that can stick to the substrate, this is to help prevent eggs being carried down stream by the water flow. Characteristic fish species are: * Brown trout (''Salmo trutta'') * Atlantic salmon (''Salmo salar'') * Bullhead (''Cottus gobio'') * Loach (''Barbatula barbatula'') Grayling zone Similar in physical characteristics to the Trout zone, although the temperature is usually slightly higher. Fish species in this zone also lay adhesive eggs. Characteristic fish species include all of the above species, with the addition of; * Grayli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Rivers Of Europe
This article lists the principal rivers of Europe with their main tributaries. Scope The border of Europe and Asia is here defined as from the Kara Sea, along the Ural Mountains and Ural River to the Caspian Sea. While the crest of the Caucasus Mountains is the geographical border with Asia in the south, Georgia, and to a lesser extent Armenia and Azerbaijan, are politically and culturally often associated with Europe; rivers in these countries are therefore included. The list is at the outset limited to those rivers that are at least 250 km long from the most distant source, have a drainage basin (catchment area, watershed) of at least , or have a mean discharge (volume, flow) of at least . Also included are a number of rivers (currently 47) that do not meet these criteria, but are very well known and/or nearly make the mark. Examples of these are the Arno, Ruhr, Saar, and Clyde. See the lists of rivers for individual countries linked to at the bottom of the page ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabolism. ''Photosynthesis'' usually refers to oxygenic photosynthesis, a process that produces oxygen. Photosynthetic organisms store the chemical energy so produced within intracellular organic compounds (compounds containing carbon) like sugars, glycogen, cellulose and starches. To use this stored chemical energy, an organism's cells metabolize the organic compounds through cellular respiration. Photosynthesis plays a critical role in producing and maintaining the oxygen content of the Earth's atmosphere, and it supplies most of the biological energy necessary for complex life on Earth. Some bacteria also perform anoxygenic photosynthesis, which uses bacteriochlorophyll to split hydrogen sulfide as a reductant instead of water, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tench
The tench or doctor fish (''Tinca tinca'') is a freshwater, fresh- and brackish water, brackish-water fish of the order Cypriniformes found throughout Eurasia from Western Europe including Great Britain, Britain and Ireland east into Asia as far as the Ob River, Ob and Yenisei Rivers. It is also found in Lake Baikal. It normally inhabits slow-moving freshwater habitats, particularly lakes and lowland rivers.B. Whitton (1982). ''Rivers, Lakes and Marshes'' p 163. Hodder & Staughton, London. Taxonomy The tench was first formally Species description, described in as ''Cyprinus tinca'' by Carl Linnaeus in 1758 in the 10th edition of Systema Naturae with its Type locality (biology), type locality given as "European lakes". In 1764 François Alexandre Pierre de Garsault proposed the new monospecific genus ''Tinca'', with ''Cyprinus tinca'' as the type species by absolute tautonymy. The 5th edition of ''Fishes of the World'' classified ''Tinca'' in the subfamily Tincinae, alongside th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bream
Bream (, ) are species of freshwater fish belonging to a variety of genera including '' Abramis'' (e.g., ''A. brama'', the common bream), '' Ballerus'', '' Blicca'', '' Brama'', '' Chilotilapia'', '' Etelis'', '' Lepomis'', '' Gymnocranius'', '' Lethrinus'', '' Nemipterus'', '' Pharyngochromis'', '' Rhabdosargus'', '' Scolopsis'', or '' Serranochromis''. Although species from all of these genera are called "bream", the term does not imply a degree of relatedness between them. Fish termed "bream" tend to be narrow, deep-bodied species. The name is a derivation of the Middle English word ''breme'', of Old French origin. Marine species The term sea bream is sometimes used for fish of the family (biology)">family Sparidae including ''Acanthopagrus'' (Australia), ''Argyrops spinifer, Argyrops'', gilt-head bream ''Sparus aurata'' (''orata'' in Italy, ''dorada'' in Spain), black seabream ''Spondyliosoma cantharus'' and red seabream '' Pagrus'' or '' Pagellus'' species; or pomfre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbid
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of both water clarity and water quality. Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid. Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. Causes and effects Turbidity in open water may be caus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Eel
The European eel (''Anguilla anguilla'') is a species of eel. Their life history was a mystery for thousands of years, and mating in the wild has not yet been observed. The five stages of their development were originally thought to be different species. They are critically endangered due to hydroelectric dams, overfishing by fisheries on coasts for human consumption, and parasites. Description European eels undergo five stages of development in their lifecycle: larva (leptocephalus), glass eel, elver, yellow eel, and silver eel. Adults in the yellow phase are typically around and rarely reach more than , but they can reach a length of up to in exceptional cases. They have 110 to 120 vertebrae. tend to live approximately 15–20 years in the wild, although captive specimens have lived for over 80 years. One such specimen known as "the Brantevik Eel" lived for 155 years in the well of a family home in Brantevik, a fishing village in southern Sweden. Ecology Eels tend to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Pike
The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus ''Esox'' (pikes). They are commonly found in brackish water, moderately salty and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a pike (Plural, : pike) in Great Britain, Ireland, most of Eastern Europe, Canada and the United States, U.S., although in the Midwestern United States, they may just be called a Northern. Pike can grow to a relatively large size. Their average length is about , with maximum recorded lengths of up to and maximum weights of . The International Game Fish Association, IGFA currently recognises a pike caught by Lothar Louis on Greffern Lake, Germany, on 16 October 1986, as the all-tackle world-record holding northern pike. Northern pike grow to larger sizes in Eurasia than in North America, and in coastal Eurasian regions than inland ones. Etymology The northern pike gets its common name from its resemblance to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Perch
The European perch (''Perca fluviatilis''), also known as the common perch, redfin perch, big-scaled redfin, English perch, Euro perch, Eurasian perch, Eurasian river perch, Hatch, poor man's rockfish or in Anglophone parts of Europe, simply the perch, is a predatory freshwater fish native to Europe and North Asia. It is the type species of the genus '' Perca''. The perch is a popular game fish for recreational anglers, and has been widely introduced beyond its native Eurasian habitats into Australia, New Zealand and South Africa. Known locally simply as "redfin", they have caused substantial damage to native fish populations in Australia and have been proclaimed a noxious species in New South Wales. Taxonomy The first scientific description of the river perch was made by Peter Artedi in 1730. He defined the basic morphological signs of this species after studying perch from Swedish lakes. Artedi described its features, counting the fin rays scales and vertebrae of the typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Rudd
The common rudd (''Scardinius erythrophthalmus'') is a benthos, bentho-pelagic freshwater Actinopterygii, ray-finned fish belonging to the Family (biology), family Leuciscidae. This species is widely spread in Europe and central Asia, around the basins of the North Sea, North, Baltic Sea, Baltic, Black Sea, Black, Caspian Sea, Caspian and Aral Sea, Aral seas. Identification Morphologically, this species is very similar to the roach (''Rutilus rutilus''), with which it can be easily confused. It can be identified by the yellow eye colour. The eye of the roach has a big red spot above the pupil, that can be more or less conspicuous. The rudd has an upturned mouth allowing it to feed easily at the top of the water. The placement of the dorsal fin is more to the rear which is even visible in very young fish. There are normally only one or two scales between the tip of the pelvic fins and the anal fins, while on the roach there are five. Also the skin of the rudd is yellowish green, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Roach
The roach, or rutilus roach (''Rutilus rutilus''), also known as the common roach, is a fresh- and brackish-water fish of the family Cyprinidae, native to most of Europe and western Asia. Fish called roach can be any species of the genera ''Rutilus'', '' Leucos'' and ''Hesperoleucus'', depending on locality. The plural of the term is also roach. Description The roach is a small fish, often reaching no more than about ; maximum length is . Its body has a bluish-silvery colour and becomes white at the belly. The fins are red. The number of scales along the lateral line is 39–48. The dorsal and anal fins have 12–14 rays. Young specimens have a slender build; older specimens acquire a higher and broader body shape. The roach can often be recognized by the big red spot in the iris above and beside the pupil. Colours of the eye and fins can be very pale, however, in some environments. In Central and Northern Europe, the common roach can most easily be confused with the common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbel (fish Species)
Barbels are a group of carp-like freshwater fish, almost all of the genus ''Barbus''. They are usually found in gravel and rocky-bottomed moderate-flowing rivers with high dissolved oxygen content, known as the '' Barbel zone''. A typical adult barbel can range from in length and weigh between and , depending on species. The name barbel derived from the Latin ''barba'', meaning beard, a reference to the two pairs of barbels, a longer pair pointing forwards and slightly down positioned, on the side of the mouth. Fish described as barbels by English-speaking people may not be known as barbels in their native language, although the root of the word may be similar. For instance, the Mediterranean barbel (''Barbus meridionalis'') is known as ''barbeau méridional'' or ''barbeau truité'' in France, but also as ''drogan'', ''durgan'', ''tourgan'', ''turquan'' and ''truitat''. Europe ''Barbus barbus'', is found throughout northern and eastern Europe, ranging north and east from Great B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Dace
The common dace (''Leuciscus leuciscus'') is a species of freshwater and brackish water ray-finned fish from the family Leuciscidae which is native to Europe but which has been introduced to other parts of the world. It is a quarry species for coarse anglers. Description The common dace differs from other members in the genus ''Leuciscus'' found in Europe by its inferior mouth, slightly longer upper jaw which has the tip of the upper lip level with the centre line of the eye and the lack of an obvious snout. It has a yellowish iris and a body which is covered in large silvery scales, the lateral line having 49–52 scales. The anal fin has a concave margin and the caudal fin is forked. The dorsal fin has 2–3 spines and 7–9 soft rays while the anal fin has 3 spines and 8–9 soft rays. The maximum size attained is a total length of . Distribution The common dace is native to Europe and northern Asia where its occurs in the basins of the North Sea, Baltic Sea, White Sea and Bar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
