Commercial larviculture ofPenaeid shrimp

Dan FeganSCRD Co. Ltd. and BIOTEC

Thailand

Thanks to

• Patrick Sorgeloos, and the organisers/sponsors of Larvi‘01 for inviting me and supporting my attendance

• Colleagues at the National Center for Genetic Engineering and Biotechnology (BIOTEC) and the Shrimp Culture Research and Development Co. Ltd. for their continued support

• The many friends and colleagues in the industry from whom I have learned much and have much still to learn

• Last, but not least, my wife Nita and the wives of our friends who have cheerfully suffered through far too many dinner table discussions on shrimp culture

World Farmed Shrimp Production

-

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

1,000.00

1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997Year

Prod

uctio

n ('0

00 m

etric

tonn

es)

Source: FAO

Major Cultured Species

Penaeus vannamei Penaeus japonicus

Penaeus chinensis

Penaeus monodon Penaeus stylirostris

Shrimp Production

BroodstockFishing

NaupliusProduction

PostlarvalProduction

Maturation& Spawning

NurseryCulture

On-growing(Farming)

Processing& Export

Domestication

NaturalSources

Postlarvae Sources

Hatchery Systems

Eastern and Western hatcheries stem from different development sources

Eastern from Japanese and Taiwanese style “Community

Culture” systems

Western from “Galveston” style, clear water systems

Asian Hatchery Types

Taiwan-styleIndoor

Thailand-styleOutdoor

Hatchery Types

The major differences between hatcheries in Asia and the West are:• Closed vs. open thelycum species• Age of PL produced• Survival rates in Asian hatcheries lower• Asian systems generally less complex• Asian systems generally smaller size• Asian industry more diversified

Increasing exposure to western methods is resulting in a convergence of technology

Major Issues in Commercial Culture

Major issues that have been identified by commercial hatchery operators over the past 10 years are:

• Broodstock and Genetics• Disease and Biosecurity• Postlarval quality• Feeds and Nutrition

Broodstock and Genetics

BroodstockBroodstock and Geneticsand Genetics

•• Availability and QualityAvailability and Quality•• Health StatusHealth Status•• NutritionNutrition•• Domestication and ImprovementDomestication and Improvement•• Specific Pathogen Free (SPF) and Specific Pathogen Free (SPF) and

Specific Pathogen Resistant (SPR) Specific Pathogen Resistant (SPR) strainsstrains

BroodstockBroodstock and genetics developments have and genetics developments have been slow but are gaining in importance. Major been slow but are gaining in importance. Major issues are:issues are:

SPF Shrimp

Non-SPF

SPF

Disease and Biosecurity

• Disease has been the number 1 concern of the shrimp industry since the mid-1990’s

• Recently, concerns have increased over the role of transshipment of PL in disease transmission

• Vertical transmission of some virus diseases from broodstock shrimp has also been raised

• Bacterial disease problems continue to plague hatchery systems

Disease

WSSV The Asian Pandemic

1993

1991/2

1993

19931993

1994

1999

Emergence and spread in the Americas

1995

1999

1997

1996

1999

1999

19992000

1999

Spawning

Egg/Nauplius Washing

Collect Fertilised Eggs

Formalin(100ppm for 30s)

Povidone Iodine(20ppm for 30s)

RunningSeawater(1-2 mins)

RunningSeawater(1-2 mins)

RunningSeawater(1-2 mins)

RunningSeawater(1-2 mins)

Collect Naupliiwith Plankton Net

RunningSeawater(1-2 mins)

RunningSeawater(1-2 mins)

Formalin(100ppm for 30s)

Formalin(100ppm for 30s)

Povidone Iodine(20ppm for 30s)Povidone Iodine(20ppm for 30s)Povidone Iodine(20ppm for 30s)

Povidone Iodine(20ppm for 30s)

RunningSeawater(1-2 mins)

Nauplius Washing

Egg Washing

Nauplius and Egg Washing

Postlarval Quality

PL quality evaluation is now an accepted procedure in most hatcheries

• Stress testing using salinity shock or formalintreatment is most common

• Microscopic evaluation is also increasingly used

• Testing for viruses using molecular diagnostics such as Polymerase Chain Reaction (PCR) is increasingly common

PL Quality Assessment

Polymerase Chain Reaction (PCR)

• Basically a method to amplify DNA of the target organism (e.g. WSSV virus)

• A small, complementary, fragment of virus DNA (the primer) is used as a template to amplify the target DNA

• The primer is placed in the PCR vial with reagents and the enzyme taq polymerase

• Repeated cycles of heating and cooling cause the DNA to separate and anneal, doubling the quantity of target DNA in the process

• This increases the concentration of DNA enough to be detected by electrophoresis

• If bands corresponding to the primer are found in the gel, the virus is present

PCR for WSSV

PCR gelof crabsinjected with WSSVM = marker (kb)1 = 0 hr2 = 12 hr3 = 24 hr4 = 36 hr

Broodstock Screening

0/522%

1/526%

2/50%

3/57%

������������ 4/5

7%

5/538%

0/522%

5/578%

Before Spawning After Spawning

Postlarval Screening

0

10

20

30

40

50

60

PL Month 1 Month 2 Month 3 Month 4 None

Positive Result Obtained

No. o

f pon

ds

0102030405060708090100

Probability of failure (%)

No. of Ponds Good Harvest Prob. Failure (%)

from data by from data by Boonsirm WithyachumnarnkulBoonsirm Withyachumnarnkul

Postlarval Screening

Pond Group NumberPonds

NumberFailed

ProportionFailed

RelativeFailure Risk*

Group 0 (PCR+ PL) 43 41 0.953 49.6Group 1 (1st Mo. PCR+) 23 12 0.522 27.1Group 2 (2nd Mo. PCR+) 40 19 0.475 24.7Group 3 (3rd Mo. PCR+) 24 9 0.375 19.5Group 4 (4th Mo. PCR+) 6 4 0.667 34.7Group 5 (Never PCR+) 52 1 0.019 NA

Total 188 86 0.457 NA*Compared to Group 5; NA = not applicable; Total # ponds studied =188; Total # ponds failing = 86 (46%)

from data by from data by Boonsirm WithyachumnarnkulBoonsirm Withyachumnarnkul

Feeds and Nutrition

• Better understanding of the importance of good nutrition

• More diverse range of feeds and feed products used

• Greater concern about health implications of live feeds and food products

• Impact on PL quality

Skeletonema

Pure Algae Culture

Artemia

Artemia Culture

Artemia Enrichment

The use of Artemia enrichment is more common in western style hatcheries than in Asian ones. Some of the reasons given are cost, ease of use and the inability of P.monodon postlarvaeto effectively use larger Artemia

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

'84 '86 '88 '90 '92 '94 '96 '98 2000

met

ric to

nnes

of r

aw p

rodu

ct

Artemia Cyst harvest (metric tonnes raw product) from the Great Salt Lake (Utah, USA) (data from USGS, 2001)

Artemia Yields

Alternative Feeds

Artemia price and availability has Artemia price and availability has prompted the use of alternativesprompted the use of alternatives

••Natural FeedsNatural Feeds–– MoinaMoina–– DaphniaDaphnia

••Formulated FeedsFormulated Feeds–– Microencapsulated dietsMicroencapsulated diets–– FlakesFlakes–– SpraySpray--dried productsdried products

Future Research Priorities

The major research priorities identified by commercial hatchery operators are:

• Genetics and Maturation• Larval Nutrition• Probiotics• Vaccines (Immune enhancers)• Disinfection Methods

Future InfluencesMany factors are likely to provide an influence on hatchery production in future. Some of these are:

• Availability of genetically improved strains• Increased pressure from farmers and consumers

– health status of PL– HACCP and responsible husbandry practices, Codes of

Practice, process documentation• Increased regulation of broodstock and postlarvae

export and import• Emphasis on efficiency of production and cost

control

Thank You