1. Lectures 9 & 10: Reproductive Biology and Behavior in fish
Biology 450: Fish Week
Lectures 9 & 10: Reproductive Biology and Behavior in fish
Scott Heppell Department of Fisheries and Wildlife Oregon State University 042 Nash Hall ,

2. Fish Reproduction

3. The H-P-G axis Hypothalamus GnRH PIT GTH I/GTH II Testis Ovary
Sex steroids

4. The HPG Feedback loops

5. Steroid biosynthesis

6. Hormonal control of oocyte maturation

7. Stages of maturation STAGE DESCRIPTION COMMENTS Stage 0 Immature
Not capable of producing viable gametes
Stage 1
Primary growth
Resting or recently mature
Stage 2
Secondary growth
Vitellogenin independent, cortical alveoli present
Stage 3
Early vitellogenesis
Vitellogenin granules present, oocyte increasing in diameter
Stage 4
Late vitellogenesis
Strong presence of vitellogenin in oocyte, gametes approaching maximum pre-spawning diameter
Stage 5
Mature/spawning/
Running ripe
Hydrated oocytes, final maturation of gametes
Stage 6
Spent
High rates of atresia, gonad loosely organized

8. Stages of gonad maturation (female)
Heppell and Sullivan FP&B 1999

9. The two-cell model

10. Vitellogenesis Hypothalamus GnRH PIT GTH I Ovary Vitellogenin Liver
Estradiol
Vitellogenin
GTH I
GnRH

11. Female final maturation

12. The female hormonal cycle

13. Water hardening

14. Hormonal control of sperm maturation

15. The male hormonal cycle

16. Male reproductive development

17. Quirks in reproductive assessment

18. Maternal effects
Bobko and Berkeley 2004

19. Maternal effects
Bobko and Berkeley 2004

20. Maternal effects
Berkeley et al 2004

21. Maternal effects
Berkeley et al 2004

22. Male mating strategies
Group spawning –Sperm competitors
Territoriality –Mate competitors
Leks
Nest guarding
Sneaker, streakers, and satellite spawners

23. Nest guarding –Lingcod

24. Phase shifts in male reproductive tactics
Immature
Mature ♀ ♂ ♀ ♂ ♂
Initial phase
Immature ♂
Initial phase ♂
Terminal phase ♂

25. ♂
Initial phase
Immature ♂
Initial phase ♂
Terminal phase ♂

26. Group spawning

27. Group spawning

28. Territoriality

29. Territoriality

30. Sex change

31. Types of hermaphroditism
Protogyny- Female first
Protandry –Male first
Simultaneous –Can spawn as both at the same time

32. ♂/♀ ♂ ♀ ♂/♀ Sex change patterns ♀ ♂ U Immature Mature Immature Mature

33. Social control of sex change

34. Social control of sex change
Warner and Swearer (1991)
Behaviors exhibited within minutes
Color changes within a day
Mature sperm within 8 days
Semsar, Godwin, Grober, Bass
Linked to Arginine Vasotosin production in the brain
Not necessarily linked to gonad production of steroids
Warner and Swearer 1991

35. Marlin explains to Nemo the sociological aspects of sexuality and parental role patterns within the context of the identity model for transgender and intersex inclusion

36. Sex ratio = 1:1 female:male

37. Sex ratio = 1.5:1 female:male

38. Sex ratio = 1:1 female:male

39. Sex ratio = 13:1 female:male

40. Department of Fisheries and Wildlife Oregon State University
Behavior, physiology, and life history comparisons in four species of grouper: What do they mean for grouper management?
Scott A. Heppell
Department of Fisheries and Wildlife
Oregon State University

41. Marine fisheries ecology at multiple scales of biological organization
Grand unifying theory
Molecule
Cell
Physiology
Behavior
Individual fitness
Populations
Species
Communities
Habitats
Ecosystems
Integration
Management

42. Male reproductive tactics, disruption of mating strategies, and “The Challenge Hypothesis”
Multiple strategies for reproductive success
Primary/territorial males
Aggressive
High androgen levels
Small testes
Secondary males (Sneakers, streakers, and satellite males)
Non-aggressive
Low androgen levels
Large testes
Also the tactic of group spawners
The challenge hypothesis (Wingfield 1984)
Territoriality
Aggression
Mate competition
Hormone positive feedback loops

43. Environmental input Behavioral interaction Sensory transduction
Testis
GTH
Behavioral
interaction
Sensory
transduction
brain
11KT +
Gene regulation
Behavior
Environmental input

44. A tale of four groupers

45. Male grouper reproductive life history analysis
Collect gonad and plasma samples from males of three different species of grouper (Nassau, red hind, and gag, with an extant dataset for red grouper)
Confirm stage of maturation w/histology
Measure androgens (Testosterone, 11-ketotestosterone)
Evaluate general patterns of androgens, sex ratio, gonadosomatic index, and spawning strategy to determine general life history patterns –identify implications for population level effects

46. Non-territorial, group
Spawning strategy
Species
Spawning strategy
Agg. size
E. striatus
Non-territorial, group
1,000-10,000's
E. guttatus
Territorial, pair ’s
E. morio
10's+
M. microlepis

47. Gonadosomatic index Species GSI Reference E. striatus 9.4
Tucker et al (from figure) 10
Sadovy and Colin 1995
E. guttatus
0.66
Sadovy et al. 1994
E. morio
0.38
Alan Collins, unpublished
0.3
Johnson 1995
M. Microlepis
1.83
Hood and Schleider 1992
0.56
Collins et al. 1998

48. Sex ratio Species Sex ratio (M:F) Location Source E. striatus
~2:1 to 1-1.4
Various Caribbean
Sadovy and Colin 1995
E. guttatus
1:4 to 1:115
Puerto Rico
Sadovy et al. 1994
1:4 to 1:8
Shapiro et al. 1993a
E. morio
1:2 to 1:6
NE Gulf of Mexico
Coleman et al. 1996
M. microlepis
1:5 to 1:76
Collins et al. 1998

49. Role of androgens in male reproduction
Testosterone
11-ketotestosterone
Sex differentiation and development
Stimulates the pituitary to induce spermatogenesis
Precursor to E2 and KT
Territoriality
Nest building
Aggression
Secondary sex characteristics
Spermatogenesis and sperm maturation
Tactic switching

50. Testosterone
ANOVA p = 0.23 A A A A

51. 11-ketotestosterone (Belize)
ANOVA p <0.0001
Tukey HSD A B B B

52. 11-ketotestosterone (Cayman)
ANOVA p <0.0001
Tukey HSD A B B B

53. T:KT ratio (pooled samples)
ANOVA p <0.001
LSD test A A
A/B B

54. Environmental input Behavioral interaction Sensory transduction
Testis
GTH
Behavioral
interaction
Sensory
transduction
brain
11KT +
Gene regulation
Behavior
Environmental input

55. Decreased Individual Reproductive Success Population level
Environmental input
Behavioral
interaction
Decreased Individual
Reproductive
Success
Sensory
transduction
Gene regulation
Behavior +
brain
Population level
(Allee) effects?
Down-regulated
GTH
Testis +
11KT

56. Conclusions
Anatomy, behavior, and physiology, correlate with spawning strategy across four species of grouper
This work presents a possible mechanism for depensation, at least in territorial species
A wider variety of species should be investigated to see whether it holds true across the majority of grouper species
For some species we should manage for sex ratio as well as overall spawning stock biomass
Critical minimum population sizes may be necessary for patterned behaviors and effective spawning
Assessing biological/resource issues across multiple scales of biological organization is important