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FISHES. Výukový materiál OR 03 - 73 Tvůrce: Mgr. Alena Výborná Tvůrce anglické verze: ThMgr. Ing. Jiří Foller Projekt: S anglickým jazykem do dalších předmětů Registrační číslo: CZ.1.07/1.1.36/03.0005 Tento projekt je spolufinancován ESF a SR ČR. FISHES.
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FISHES Výukový materiál OR 03 - 73 Tvůrce: Mgr. Alena Výborná Tvůrce anglické verze: ThMgr. Ing. Jiří Foller Projekt: S anglickým jazykem do dalších předmětů Registrační číslo: CZ.1.07/1.1.36/03.0005 Tento projekt je spolufinancován ESF a SR ČR
FISHES • the most numerous class of vertebrates • the oldest proofs of their existence are known from Paleozoic –440 million years ago • in all types of water • various body shapes • skeletons have different mass of ossification
FISHES • gas bladder – filled with gases with overwhelming nitrogen, it unweights the fish body and helps keep it in a particular position and in various depths • stream organ – noticeable as the lateral line, orientation in the environment • there are over 25 000 fish species in the world
FISHES • gill is protected from the outside • the body is usually provided with a symmetrical caudal fin, pair fins pectoral and pelvis and non-pair dorsal and anal fins • fins are stiffened with osseous fin races • some species have a apidose fin (salmon)
FISHES • fresh water fishes: • all fishes living in our country are usually located in four basic types of flowing water – fish zones • 1) trout zone : upper fast flowing section (mountain streams) • 2) grayling zone: streams and rivers on foothills
FISHES • 3) barbel zone: middle section of rivers with broad river-basins and fast streaming water • 4) bream zone: lowlands, slowly flowing water with dead-end branches • this natural division can be disturbed by the human activity
FISHES • prevailing fishes in our fauna are carp fishes • common carp: • originally wild • it lived in rivers • domesticated - fishponds
FISHES • crucial carp: • similar to common carp • it has not got whiskers around the mouth • polluted water does not bother it • common tench: • tiny scales, deep under the skin • stagnant water
FISHES • common roach: • red eyes • the most common carp fish
FISHES • other members of our fauna: • river bass: • nice colourful fish • in all types of water • common zander: • delicious low-fat meat
FISHES • common trout: • salmonoid fish • fast flowing water rich in oxygen • mountain, foothill areas • common pike: • sport fish • slowly flowing, stagnant water
FISHES • big catfish: • our biggest fish • slowly flowing, stagnant water • river eel: • serpentiform body • on the bottom • active at night
FISHES • COMMERCIAL IMPORTANCE OF FISH: • food for humans • fish meat covers 15 % of food of animal origin • freshwater fishing in the Czech republic focuses mainly on fish farming in fishponds • sea fish are an important part of national economics for sea countries (herring, cod, mackerel, tuna…)
Review: • 1) What are the main features of fish? • 2) When did the first fishes appear? • 3) Gas bladder is used for………….. • 4) How can fish orient in the environment? • 5) Can a trout be caught in the pond? • 6) Which is our most common fish?
Source: • DOBRORUKA, Luděk J. Přírodopis pro 7. ročník základní školy. 1. vyd. Praha: Scientia, 1998, 152 s. ISBN 80-718-3134-4 • Obrázky: http://commons.wikimedia.org (osvobozeno od autorských práv)