1. 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

2. 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

3. 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

4. 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)

5. 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

6. 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

7. FISHES prevailing fishes in our fauna are carp fishes common carp: originally wild it lived in rivers domesticated - fishponds

8. CARP

9. 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

10. CRUCIAL CARP

11. COMMON TENCH

12. FISHES common roach: red eyes the most common carp fish

13. COMMON ROACH

14. FISHES other members of our fauna: river bass: nice colourful fish in all types of water common zander: delicious low-fat meat

15. RIVER BASS

16. FISHES common trout: salmonoid fish fast flowing water rich in oxygen mountain, foothill areas common pike: sport fish slowly flowing, stagnant water

17. COMMON TROUT

18. COMMON PIKE

19. FISHES big catfish: our biggest fish slowly flowing, stagnant water river eel: serpentiform body on the bottom active at night

20. BIG CATFISH

21. EEL

22. 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…)

23. 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?

24. 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)http://commons.wikimedia.org