Invited presentation given by Dr Curtis Lind at the 17th International Congress on Animal Reproduction (ICAR), Vancouver, Canada, 31st July, 2012. SUMMARY: To satisfy increasing demands for fish as food, progress must occur towards greater aquaculture productivity whilst retaining the wild and farmed genetic resources that underpin global fish production. We review the main selection methods that have been developed for genetic improvement in aquaculture, and discuss their virtues and shortcomings. Examples of the application of mass, cohort, within family, and combined between-family and within-family selection are given. In addition, we review the manner in which fish genetic resources can be lost at the intra-specific, species and ecosystem levels and discuss options to best prevent this. We illustrate that fundamental principles of genetic management are common in the implementation of both selective breeding and conservation programmes, and should be emphasized in capacity development efforts. We highlight the value of applied genetics approaches for increasing aquaculture productivity and the conservation of fish genetic resources. http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0531.2012.02084.x/abstract

1. Selective breeding in fish and conservation of
genetic resources for aquaculture
Curtis E Lind, RW Ponzoni, NH Nguyen, and HL Khaw
The WorldFish Center ICAR 2012, Vancouver 31st July

2. Introduction
Differences between livestock and fish
Selective breeding approaches in fish
Genetic resources for aquaculture
Concluding remarks

3. Introduction
Differences between livestock and fish
Selective breeding approaches in fish
Genetic resources for aquaculture
Concluding remarks

4. Introduction
Differences between livestock and fish
Selective breeding approaches in fish
Genetic resources for aquaculture
Concluding remarks

5. Introduction
Differences between livestock and fish
Selective breeding approaches in fish
Genetic resources for aquaculture
Concluding remarks

6. Introduction
Differences between livestock and fish
Selective breeding approaches in fish
Genetic resources for aquaculture
Concluding remarks

7. aquaculture provides nearly half of all food fish

8. mostly freshwater species farmed in Asia

9. key constraints are lack of feed, seed and capacity

10. <10% is from genetically improved strains

11. fish breeding and genetic resources major issues

12. livestock vs. fish

13. High
100 – 10,000 progeny
per female per cycle
reproductive rate
Low
< 10 progeny
per female per cycle

14. 1-3 years
generation interval
3-8 years

15. few defined breeds
no breed societies
domestication
many defined breeds
preserved by keepers or
breed societies

16. often wild-caught
producer or
hatchery owned
source of breeders
stud farms
producer-owned
domesticated stock

17. greater selection intensity,
response per generation
livestock vs. fish
greater annual genetic gain
risk of inbreeding greater

18. greater potential for rapid
dissemination at scale
livestock vs. fish focus on developing and
maintaining strains
focus on minimizing impact
to wild genetic resources

19. Selective breeding in fish

20. Several approaches to genetic
improvement feasible with fish
hybridization transgenesis
cross-breeding
chromosome
manipulation
selective breeding
only approach where gains are
cumulative and permanent

21. Several approaches to genetic
improvement feasible with fish
hybridization transgenesis
cross-breeding
chromosome
manipulation
selective breeding
multiple selection approaches
with varying complexity

22. Several approaches to genetic
improvement feasible with fish
“combined”
selection
within-family selection
cohort selection
individual (mass)
selection
selective breeding
multiple selection approaches
with varying complexity

23. Application in fish lags far
behind livestock or crops
“combined”
selection
within-family selection
cohort selection
individual (mass)
selection
selective breeding
multiple selection approaches
with varying complexity

24. age unknown
pedigree and genetic
relationships unknown
individuals selected
high risk of on phenotype only
inbreeding (measurable alive)
μ
150 g 300 g 550 g
Individual selection

25. limited success in fish due
to high inbreeding rates
can be managed with controlled mating
and standardized family contributions
challenging in
developing countries
Individual selection

26. selection done within inbreeding limited by
cohort or group mating between cohorts
(fe)males rotate
field personnel comfortable with this design
Cohort selection

27. requires family
identification
families reared in separate
tanks, hapas, cages
high within-family selection
intensity possible
inbreeding easily controlled
by rotational mating
Within-family selection

28. successfully applied FaST strain at Central Luzon
in tilapia State University, Philippines
genetic gain for body
weight estimated at 12%
per generation after 12
generations
easily managed but
requires greater inputs
Within-family selection

29. utilizes information from can produce single index
individual plus relatives, incorporating multiple traits
linked by pedigree
uses Best Linear Unbiased
Prediction (BLUP) to estimate
breeding values (EBVs)
BLUP accounts for systematic effects (e.g. sex, batch, age) and
maternal, common environmental effects
Combined selection

30. BLUP permits selection
of traits unmeasured on information from relatives
candidates
related individuals
likely have similar EBVs
inbreeding can be an
issue if unchecked
successfully applied in salmon, tilapia, Indian carps
Combined selection

31. ample evidence that constraints are usually
selective breeding can be financial and lack of
successful in fish adequate capacity
current breeding programs
mostly focus on growth
improvements
unfavourable correlated
traits must be monitored
Breeding programs in fish

32. conservation
of fish genetic
resources

33. genetic resources:
fish genetic genetic material of actual or potential value
(Convention on Biological Diversity)
resources
genetic resources for food “fish” often extended to
and agriculture derived from include other aquatic
fish species organisms

34. biological diversity often categorized in
fish genetic hierarchical levels
resources
intra-specific genetic diversity

35. biological diversity often categorized in
fish genetic hierarchical levels
resources
intra-specific genetic diversity
species diversity

36. biological diversity often categorized in
fish genetic hierarchical levels
resources
intra-specific genetic diversity
species diversity
ecosystem diversity

37. biological diversity often categorized in
fish genetic hierarchical levels
resources
intra-specific genetic diversity
(population diversity)
species diversity
ecosystem diversity

38. intra-specific
concerned with management of
genetic and resource at population level
population
level maintenance of gene
variants (alleles)
many alleles will characterize a population

39. intra-specific problem is...
genetic and fish vulnerable to rapid loss of
diversity
population
level difficult to maintain pedigree
high reproductive rate
large populations from
a few breeders
exaggerated genetic drift
low effective population size (Ne)
molecular tools provide some assistance

40. intra-specific problem is...
genetic and fish vulnerable to rapid loss of
diversity
population
level can be managed through proper
hatchery practices and training
…and developed a production level
industry structure diversity not critical
if maintained in
nucleus
generally not
present

41. species and consider consequences of interactions
among species or populations
ecosystem
level
fish are cultured in many
environments and systems

42. species and consider consequences of interactions
among species or populations
ecosystem
level
fish can readily escape

43. species and consider consequences of interactions
among species or populations
ecosystem
level
fish can readily escape
and are difficult to recapture
managing impacts of
escapees is a major
concern
wild genetic
resources

44. species and consider consequences of interactions
among species or populations
ecosystem
level
non-natives can proliferate
managing impacts of
escapees is a major
concern
wild genetic
resources

45. species and consider consequences of interactions
among species or populations
ecosystem
level
fish can hybridize easily
or breed with wild relatives
managing impacts of
escapees is a major
concern
wild genetic
resources

46. issues at this level are far
species and more complex
ecosystem
level
difficult to predict
likely impacts
often must incorporate
broader environmental
management
strong
governance, regulation
and science required

47. scope for substantial gains through
selective breeding programs in fish
essential
for future aquaculture
development
concluding remarks
ample proof of success
significant progress can
occur with limited inputs if
properly trained

48. genetic improvement should not
come at the cost of conservation
vice versa
genetic management
concluding remarks
necessary for both
government support
important for both

49. photo credits:
1. Flickr/ Dr DeNo full manuscript:
7-11. Flickr/ PraYudi Lind, CE, Ponzoni, RW, Nguyen, NH and Khaw, HL. (2012), Selective
12-18. top: Flickr/ Robin Robokow breeding in fish and conservation of genetic resources for aquaculture.
bottom: Flickr/ ILRI Reproduction in Domestic Animals, 47 (Suppl.4): 255–263.
19. Flickr/Johnny Peacock
doi: 10.1111/j.1439-0531.2012.02084.x
20-23. Flickr/ Guy Mason
25. Curtis Lind
26. Flickr/ wockerjabby thanks to:
27. top, middle: Curtis Lind ICAR 2012 organizers, chair and hosts
bottom: Flickr/Marcodvz
28. Flickr/ Seafdec
30. mymakolet.com
31. anonymous/CEL collection
32. Flickr/ ~ Martin ~
34. Wikipedia
36. Flickr/ Michael McCullough
37. Flickr/ Mike_tn
38.
39.
41.
Flickr/ Suneko
Flickr/ US Fish & Wildlife Service
Flickr/ linuts
acknowledgements
42. anonymous
43. Flickr/ Ray Morris 1
44. Illinois Natural History Museum
45. www.elusivetrout.com
46. Flickr/ Patrick Choi
47-48. Peter Fredenburg
49. Bill Reid
tilapia illustrations:
Susanne Weitemeyer,
Scandinavian Fishing Year Book