Reading Assignment:

1. Reading Assignment: • Chapter 10--Sensory Perception Fish ear end

2. Growth: • Longevity • unconfirmed reports of carp 200-400 yr. • authenticated records for carp 50 yr. • large fish-few > 12-20 yr. • some marine spp > 100 yr. thornyspines, orange roughy • many small spp-2 yr. or less (sardines, anchovies) Note: aging with scales, bones, otoliths end

3. 19 feet long; 350 pounds end

5. Growth: Other Generalities • females often larger than males • growth rate varies with temp. • longevity inversely proportional to temp. • stress reduces growth • dominance hierarchies - dominant get food • overcrowding can lead to stunting • indeterminate growth - grow throughout life • growth highly variable - can loose weight end

6. Bioenergetic Definition of Growth • energy accumulation (calories) vs. length or weight end

7. Bioenergetics continued: • Energy Budget: I = M + G + E where: I = ingested energy M = energy expended for metabolism G = energy stored as growth E = energy lost to environment end

8. heat G M Bioenergetic Energy Budget: I E end

9. Bioenergetics continued: Ex: M = energy for body repair maintenance activity digestion end

10. Bioenergetics continued: Ex: E = energy in feces ammonia, or urea mucus epidermal cells end

11. Terms: • Standard Metabolic Rate • maintenance met.; no growth, no activity • Routine Metabolic Rate • typical met.; routine growth & activity • Active Metabolic Rate • max. aerobic metabolism end

12. { Factors Affecting Growth: Temperature routine active standard scope Metabolic Rate activity growth Where would growth be best? Temperature end

13. Factors Affecting Growth: Temperature normal O2 reduced O2 Metabolic Rate reduced scope reduced growth Temperature end

14. Growth will not occur at low O2 Ex: LMB cease growing below 5 mg/L end

15. O2 regulator (most species) O2 conformer 0 8 4 Factors Affecting Growth: Dissolved oxygen Routine Metabolism critical O2 concentration Dissolved Oxygen mg/L end

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17. Effect of Ammonia on Growth: • NH3 is more toxic than NH4+ • relative Conc. Depends on pH • at 24C: 0.5% NH3 at pH = 7 34% NH3 at pH = 9 • 96 hr LC50 = 3.8 mg/L NH3 • as low as 0.6 mg/L for some spp. • slow growth & tissue damage at 0.006-0.34 mg/L (continuous exposure) Aquarium problems Transport problems end

18. Effects of other factors on growth: • Growth reduced at sub-optimal salinities end

19. scope active metabolic rate - standard metabolic rate Model: effect of environment on fishes scope simplify Metabolism Environmental Variable end

20. hypothetical physical or psychological stress Stress stressed tolerance lethal low lethal high lethal low lethal high tolerance Model continued: Scope Environmental Variable end

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22. salmon; smelt Overview of Reproduction: Varies greatly among fishes 1. behavior: • courtship behavior • nest building • parental care versus no care • mixed behaviors • sneaker bass • sneaker and mimic bluegills • migration • anadromy- spawn in FW, mature in SW • catadromy - spawn in SW, mature in FW eels end

23. Anadromous salmon end

24. Overview of Reproduction continued 2. Anatomy: • claspers - chondrichthyes • gonopodium - Poeciliidae • sexual dimorphism • males larger in territorial species (salmon) • females usu. larger in others end

25. catshark with claspers claspers end

26. black molly gonopodium end

27. gonopodium end

28. Sexual dimorphism in salmon: female male end

29. Overview of Reproduction continued 3. Physiology • sex chromosomes: • XY = M; XX = F (most) • ZZ = M and ZW= F(Poeciliidae & Tilapia spp) • some fishes have 3 or more sex chromosomes • sex not under complete genetic control • hermaphrodites--both sexes (many in Serranidae) • usu. one sex at a time • exception hamlet (serranid) • sex changes--bluehead wrasse end

30. bluehead wrasse (Labridae) male • harem • dominance hierarchy • dominant F becomes M female & juv. end

31. Overview of Reproduction continued 3. Physiology continued • parthenogenesis -- egg develops w/o fertilization • Ex: Amazon molly • all female • produce genetic clones • Ex: gynogenesis in Phoxinus (Cyprinidae) • all female • gynogenesis--sperm required, DNA from male not incorporated in embryo end

32. Reproductive Modes in Fishes: • Oviparous -- egg layers; most fishes • internal or external fertilization • Ovoviviparous • internal fertilization • eggs hatch internally • live birth • yolk only nutrition • EX: Lake Baikal sculpins • marine rockfishes • some sharks end

33. Lake Baikal Approx. 400 mi. long 5315 ft > 1 mi. deep end

34. Reproductive Modes in Fishes: continued • Viviparous--live birth • nutrition provided directly by mother • EX: embryonic cannibalism -- a few sharks • fins against uterine wall -- surf perches • placenta-like structures--pericardial tissues in Poeciliidae end

35. nurse shark embryos end

36. lemon shark pup yolk sac and stalk function like placenta and umbilical cord end

37. Reproductive Strategies: Energy Investment egg size: number vs. survivability carp > 2,000,000 salmon 1500-2000 parental investment: energy vs. surviv. nest building parental care mouth brooders--cichlids; ariids end

38. Parental care: pouches (seahorses, pipefishes) end

39. male female end

40. Parental care: guarding smallmouth bass--males bullhead--both sexes end