1. Reading Assignment: Chapter 23: Perciformes end

2. Notice: Projects Due: Wednesday 10 December end

3. Behavior & Communication: 1. Schooling 2. Feeding 3. Aggressive Behavior 4. Dominance Hierarchies 5. Resting Behavior end

4. 1. Schooling - moving in close coordinated association 25% of fishes school –herring schools to 4.5 billion m 3 @ density 0.5-1 fish per m 3 1/7 th vol. of Lake Sakakawea –consider: Lake Sakakawea 30 billion m 3 200 mi long; 185 ft max depth end

6. Advantages of Schooling: Reduced risk of predation –school may appear as large organism –collective alertness –predator confusion difficulty of selecting target (flock-shooting) movement camouflage end

7. sergeant major end

8. Advantages of Schooling continued: Hydrodynamics--energetic efficiency in swimming –drafting –snout-cone effect –similar to V-formation in birds 25 birds could get a 70% increase in distance for a given energy expenditure end

9. Hydrodynamics of Schooling thrust streamlines turbulence end

10. Carangidae--bigeye jack school end

11. diagonal banded sweetlips end

12. Advantages of Schooling continued: increased efficiency in finding food increased reproductive success end

13. 2. Feeding Behavior Generalists--wide variety of prey –omnivores -- catfishes Specialists--specific prey –herbivores -- plant/algae eaters –planktivores –piscivores -- fish eaters –extreme specialists scale-eating cichlids parrot fishes -- coral cookie-cuter sharks end

14. Scaridae--parrot-fishes end

15. cookie cutter shark end

16. cookie cutter shark end

17. goblin shark caught at depth of 960 m end

19. Feeding Behavior continued: Opportunists -- take advantage of abundant prey –even if outside normal mode of feeding –non-surface feeders may feed at surface during mayfly hatch –trout feeding on insect hatches end

20. Foraging Factors: prey size versus mouth size energetic efficiency--energy spent versus energy gained –prey distance –ease of capture - speed; maneuverability –handling - spines; armor –ease of digestion - composition; scales; bone –energy/nutrient content end

22. 3. Aggressive Behavior Territoriality - some defend territories, generally for a limited resource –mates –breeding sites –feeding territories –Ex. Tilapia in thermal gradient end

23. Aggressive Behavior continued: Aggressive encounters: –charges –nips –flare fins –lateral displays –submissive behaviors end

24. Aggressive Behavior continued: Factors affecting aggressive advantage: –size –prior residency –result of previous encounters Dominance Hierarchies –often established in interacting groups –Advantages/Disadvantages? end

26. 4. Resting Behavior “sleeping” or inactive observed in many species day night dusk dawn schools become disorganized some change color some do not react to vision or touch end

28. Communication Pheromones--already covered 1. Visual Signals 2. Auditory Signals end

29. 1. Visual Signals: Color -- important in visual comm. –pigments: carotenoids - reds, yellows (contribute to green) melanins - dark red, brown, black end

30. Color continued: –Structural colors: (reflected light) purines - reflective (colorless) –ex: guanine (iridiophores) cells containing guanine –iridescence: produced when light waves are reflected in parallel end

31. carotenoids clown fish end

32. Salvelinus fontinalis--brook trout carotenoids end

33. carotenoids diagonal banded sweetlips end

34. melanins end

35. Poeciliidae -- black mollymelanins end

36. Etheostoma nigrum - johnny dartermelanins end

37. guanine blue marlin end

38. guanine Hiodon alosoides -- goldeye end

39. guanine Dorosoma petenense -- threadfin shad end

40. guanine Sphyraenidae -- barracuda end

41. Example of coloration: Campostoma--stoneroller end

42. Example of coloration: end

43. Etheostoma exile--Iowa darter Example of coloration: end

44. Lepomis cyanellus -- green sunfish Example of coloration: end

45. Chromatophores -- pigment cells branched cells contain pigments or reflective crystals pigments can be concentrated in center or distributed in branches control: neuro-endocrine system

46. Chromatophore pigment Vision & Nerve control Normal coloration

47. EX: experiments with flounders--role of vision Pleuronectiformes

48. adrenaline Chromatophore pigment Lighter color

49. acetylcholine Chromatophore pigment Return to normal color

50. Function of coloration thermoregulation - dark absorbs heat; light reflects heat intraspecific communication evasion of predators

51. squirrelfish red coloration Examples: red--first wavelength to be filtered

52. red coloration short distance advertisement northern redbelly dace

53. countershading

55. poster colors --complex color patterns (common in reef fish)

56. Function of Poster colors: advertisement of territory ownership contact between foragers intraspecific communication of sex, status, maturity (Labridae, Scaridae) predator avoidance--cryptic on color background aposmatic coloration--advertisement of danger (poison; spines)

57. poster colors butterfly fish

58. poster colors

59. queen angelfish

60. poster colors

61. lionfish--aposmatic coloration

62. disruptive coloration--patterns that disrupt outline flicker fusion--patterned fish against patterned background

63. disruptive coloration camouflage

64. disruptive coloration camouflage

65. disruptive coloration camouflage

66. disruptive coloration camouflage guitarfish

67. disruptive coloration camouflage leafy seadragon

68. eye concealment

71. eye enhancement French angelfish

72. eye enhancement moray eel

73. eyespots

74. lateral stripes common in schooling spp For orientation & pred. confusion

75. lateral stripes

76. polychromatism different colors in different individuals –ex: midas cichlid gold morphs win comp. for food rarely common in wild (prob. due to pred.) –ex: annual killifish brightly colored morphs dominant--greater reproductive success early dull forms live longer--rep. success later in season

77. special patterns Ex: egg-shaped spots on male cichlids –mouth brooders –females take eggs into mouth after laying –attempts to pick up “dummy” eggs aids fertilization

78. photophoresdragonfish Light producing cells Most common in twilight-zone fishes 300-1000 m Self-liminescence--liciferin/luciferace chem. react Symbiotic luminescence--luminescent bacteria in gland-like structures

79. photophores lanternfish