1. Characteristics of Water Continued Implications for fish biology end 2006

2. Many other substances ionize in water: Salts: NaCl Na + Cl - + Bases: NH 3 + H 2 O NH 4 + OH - + Acids: H 2 CO 3 H+H+ HCO 3 - + carbonic acid ammonia bicarbonate ammonium end

3. Density of water H H O O H H O H H HH O HH O Ice: voids voids. Covalent bond-share electrons Hydrogen bond-electrostatic end

4. As temp of ice increases: Molecules vibrate more rapidly hydrogen bonds begin to break free molecules fill voids water becomes densest vibrations increase in amplitude; intermolecular distances increase TEMP. 0 °C 3.94 °C 100 °C Density g/ml Ice 0.917 water 0.9999 1.000 0.996 Significance with respect to life? end

5. Thermal Stratification: epilimnion hypolimnion thermocline less dense more dense end

7. Density of water increases slightly with salinity Salinity 0 / 00 Density % 0 35 100 102.9 (sea water) end

8. Viscosity: Viscosity - tendency for a fluid to resist motion within itself due to attraction among molecules. Salinity - little effect on viscosity (slight inc) Characteristics of water continued: end

9. Comparative Viscosities: SubstanceViscosity kg/m/s acetone0.326 x 10 -3 freshwater1.002 x 10 –3 20 C saltwater 34.8 g/l1.072 x 10 –3 20 Cmercury1.554 x 10 -3 glycerin1.490 end

10. Temperature vs Viscosity Temperature C Viscosity 10 -3 kg/m/s Viscosity doubles as temp. decreases from 25 to 0 C/ Viscosity of water offers approx. 100 x the resistance to movement as air. 0 0.5 1 1.5 2 01020304050 end

12. Surface Tension Defn--inward adhesion of molecules at surface due to attraction of molecules surface tension of water is higher than any other liquid except mercury increases slightly with salinity decreases with temp end

13. spider jumping end

14. water strider end

16. Specific heat Defn--amount of energy (in calories) required to raise temperature of 1 g of substance 1 degree C water is standard with value of 1 (varies with temp but close to 1) end

17. Comparison of specific heat SubstanceSpecific heat copper0.09 rocks0.2 ice0.5 water (distilled)1.0 liquid ammonia1.23 liquid hydrogen3.4 end

19. Effects of Properties of Water on Living Organisms Density & Buoyancy Archimede’s Principle--when an object is immersed in a fluid, an upward force acts on it, equal to the weight of the fluid it displaces end

20. air water neutral buoyancy positive buoyancy positive buoyancy negative buoyancy positive buoyancy = H2OH2O > H2OH2O = = = Archimedes Principle neutral buoyancy Fish? end

21. Densities of Biological Substances: SubstanceDensity g/cm 3 lipids0.9 freshwater (20 C)1.002 saltwater (20 C)1.072 muscle1.05 bone (dry)1.1 silaceous cell walls2.0 cellulose1.5 calcium carbonate3.0 end

22. Slight negative buoyancy--densities of most aquatic organisms are close to that of water (usually slightly more dense) fish densities--1.06-1.09 g/cm 3 end

23. Support Aquatic organisms are well supported due to density similarities between water and aquatic organisms Effects--reduced energy expenditure reduction or lack of support tissues end

24. Streamlined shapes Active fish tend to be streamlined due to high energy required for locomotion in water end

26. Ecological Groups of Fishes Six general categories body shape habitat general life style Clues to lifestyle Doesn’t fit all fishes 1.Rover predators 2.Lie-in-wait predators 3.Surface oriented fishes 4.Bottom fishes 5.Deep-bodied fishes 6.Eel-like fishes http://www.und.nodak.edu/instruct/skelsch/425~1.htm end

27. 1. Rover Predators-- moving hunters Terminal mouth Fins evenly placed (maneuverability) stream-lined brassy minnow end

28. Ex: Salmonidae brook trout end

29. Ex: Percidae walleye end

30. Ex: Centrarchidae (basses only) largemouth bass end

31. 2. Lie-in-Wait predator (piscivores) Terminal mouth; large w needle-like teeth Stream-lined; often elongated and thin Head flattened northern pike end

32. Lie-in-Wait predator (continued) Caudal fin large Dorsal and anal fins placed posteriorly Cryptic coloration end

33. Esocidae-pikes, pickerel, muskie muskellunge end

34. Lepisosteidae - gars longnose gar end

35. needlefish end

36. Sphraenidae -- barracuda longnose gar end

37. 3. Surface-Oriented fishes Often small Upward tending mouth (superior or superterminal) Dorsoventrally flattened head Adapted to surface life Poeciliidae-live bearers guppies mollies Gambusia mosquitofish end

38. Four-eyed fish end

39. Cyprinodontidae-pupfish, killifish banded killifish end

40. betas archerfish Other surface oriented fishes Gambusia end

41. 4. Bottom fishes (benthic) Swimbladder reduced or absent flattened dorsoventrally (depressed) Atlantic halibut end

42. Bottom fishes continued Specialized structures: sensory structures barbels, fin rays modified fins (darters, clingfishes) barbels end

43. sea robin end

44. flounders soles tonguefish Pleuronectiformes-flatfishes end

45. hog choker end

46. Acipenseridae--sturgeons lake sturgeon end

47. Skates & rays end

48. 5. Deep-bodied fishes Laterally flattened (compressed) Dorsal and anal fins long Pectoral fins high on body Pelvic fins thoracic Mouth protrusible Fin spines French angelfish lookdown butterfly fish maneuverability end

49. Centrarchidae-crappies & sunfishes bluegill end

50. 6. Eel-like fishes-- elongated bodies Paired fins reduced or absent Dorsal and anal fins long Scales small or absent Flexible bodies Adapted for small crevices end

51. American eel slime eel snake eel end

52. moray eel end