Tilapia Aquaculture

1
Tilapia Aquaculture An Overview Selection of
Broodstocks and Hatchery Systems

• Kevin Fitzsimmons University of Arizona,
  Professor
• World Aquaculture Society, Immediate
  Past-President
• American Tilapia Association, Sec./Tres.
• Pablo Gonzalez Alanis
• Universidad Autonoma de Tamaulipas, Professor
• World Aquaculture Society, Student Liaison
• Program Coordinator, Aquaculture TIES
• Hermosillo, Son. Mexico
• Dec. 2, 2005

2
Tilapia breeds

• Proper selection of fish for your type of
  production system is second most important
  decision (after marketing)
• There are several species, hybrid strains, and
  breeding programs available
• Goals are fast growth, good FCR and mostly male
  fish
• Must determine if farm will buy fry or
  fingerlings or attempt to maintain own hatchery

3
Tilapia species and breeds

• O. niloticus (Nile Tilapia) Most commonly used
  tilapia 70-75 of global production
• O. aureus (Blue Tilapia) about 5 of global
  production
• O. mossambicus - (Mossambique or Java Tilapia)
  about 5 of global production
• Red hybrid strains - O. mossambicus and/or O.
  urolepis-hornorum (Wami River Tilapia) crossed
  with O. aureus and/or O. niloticus) about 20 of
  global production

4
Tilapia species and breeds

• Match fish to production system
• Brackish water Red hybrid strains
• Pond systems O. niloticus or red strains
• Cage systems O. niloticus or red strains
• Intensive (tanks, raceways or recirculating
  systems) - O. niloticus or red strains
• Cooler temperatures O. aureus or hybrids
• South Africa and California (only O. mossambicus
  and hybrids)

5
Genetic Improvements in Tilapia
(From Mair, G., 2002)
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O. niloticus strains and breeding programs

• G.I.F.T. - Genetically Improved Farmed Tilapia
• Chitralada From a strain kept at the Chitralada
  Royal Palace in Thailand
• Genomar A Norwegian-Brazilian breeding program
• G.I.F.T.-EXCEL Additional breeding program
  continued in the Philippines
• At least 3 more family selection programs

7
Red Tilapia strains

• Red O. mossambicus mutants found in 1970s
• Backcrossings fixed the mutation
• Taiwan, Florida, Israeli, and Stirling (Scotland)
  strains were developed
• These were repeatedly out-crossed to other
  species (New strains in Jamaica, Arizona,
  Colombia, Ecuador, Thailand, China, Vietnam)
• Many red strains now available, most with high
  salinity tolerance

8
Methyltestosterone technique

• Feed fry with food containing MT (60mg 17a-MT/kg
  of feed) for 21 days
• For product to be sold in US, MT feed should be
  purchased from approved supplier
• Females develop as males, males unaffected
• Isotope labeling studies demonstrate that MT in
  fish is below detectable limits 30 days after
  last feeding
• 90 develop as male fish

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YY technique

• Treat fry with estrogen
• Males develop as females
• These XY females are mated to normal males (XY)
• ¼ XX ½ XY ¼ YY
• XY and YY males are progeny tested to XX
• Fathers of all male fry (XY) must be YY
• YY males can be sold and crossed to normal
  females (XX) to get almost all male progeny (XY)

10
The YY male technology
(GMT)
(From Mair, G., 2002)
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YY technique

• FishGen, is a UK based company which sells YY
  males and fry from YY male hatcheries in several
  countries
• Genetically Male Tilapia (GMT) is their brand
  name
• Food fish are two generations removed from being
  treated with hormone and can be considered
  organic.
• Technique could be copied, but hatchery would
  need several years and many qualified biologists
  to develop a program

12
Hybrid crosses

• Several inter-specific crosses yield high
  proportion of males (70-90)
• Requires maintenance of two pure species breeding
  lines
• This technique was developed in Israel and
  Chinese claim to do this with GIFT niloticus
  crossed with O. aureus. However, use of MT is
  suspected.

13
Hatchery styles

• Normally stock 1? and 3?
• Eggs are incubated by female
• Eggs can be collected and hatched in jars or
  trays
• Or hatched by mother and fry collected when free
  swimming

14
Dr. Raul Ponzoni and World Fish Center program in
Malaysia .
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Typical spawning or fry rearing hapas
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Pond spawning vs. tank spawning

• Pond or hapa rearing for large numbers
• Tank spawning for small numbers and directed
  rearing programs

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Jar and trayegg hatching

• Jar hatching better for large numbers with little
  supervision
• Tray hatching better if labor is abundant and
  high survival is important

18
Technologies to reduce externalities(MT use and
discharge)

• Reduce or eliminate MT use (mixed sex, cages, YY,
  hybrids, salt-water culture)
• Use phytochemicals to induce sex change (still
  experimental)
• Remove effluent MT with carbon, UV, or ozone

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Post hatch

• Swim-up fry allowed to leave hatching vessel
• Usually collected in screened buckets or trays
• Start sex reversal or start normal feeding in
  hapas

20
Fry moved to pre-growout around 1 g