Feeding Patterns of Prawns

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• Feeding Patterns of Prawns
• by
• Peter Blyth
• Acknowledgements
• Gold Coast Marine Aquaculture, Jacobs Well, QLD
• CSIRO (CMAR), Cleveland, QLD
• TAWEE Farm, Thailand
• Bayer, Thailand
• Faculty of Fisheries, Kasetsart University,
  Thailand

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Factors that impact on Feeding

• Water Temperature
• Oxygen
• Feed composition
• Spatial feed distribution
• Biomass/stocking density
• Moon phase/moulting
• Size
• Barometric pressure/salinity/rainfall
• Predators
• Timing of feeding
• Behavioural (competition)
• Chemical composition of water (pH, ammonia etc)
• Pond flora and fauna
• disease

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Atlantic salmon Salmo salar
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Feeding to Rationoptimum
Under Feeding - Over Feeding
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Reduced Environmental Impact Cage culture (sea
bass in EU)
AQ1 Feeding Control
Average 23.5 (SD 1.38) decrease in predicted
sediment carbon input over the production period
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Pellet leaching
After Smith et. al., 2002
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Equipment SF200 Sound Feeding System

• System Components
• Hydrophone
• Controller
• DO/Temp Probe
• Management Software
• Enviro. alarms

Comprised a CORTEX-A8 microprocessor, HTI-96-MIN
hydrophone, Sterner circular 12VDC. Data
communications was via WLAN to a PC managed by
AQPC software
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Delivery Methods
Blower feed tray
By hand feed tray
Feeder hydrophone
Feeder feed tray
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Auto-feederssingle or three phase circular
spreaders
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Instantaneous feed response
L.vannamei
P.monodon
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Black Tiger Farm Gold Coast Marine Aquaculture

• Jacobs Well, SE Queensland
• P. monodon
• X53 -1h ponds and several 0.3h ponds
• Annual production 500-700
• Use CP and Ridley Aquafeed pellets
• 1 crop per year
• Salinity range 20-40ppt
• Temperature range 20-30C

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Trial 2 SF200r auto in Commercial Pond

• 1 hectare ponds
• Pond 1 - SF200r/ 4 auto-feeders G18
• Pond 2 control (compared to Hand fed G17
• Both stocked in 25th Sept 2010
• SF200 pond 392,000, Blow-Fed 368,000 pls each

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Tawee White shrimp farm
Surat Thani, Thailand L. vannamei X200 -1h
ponds Use CP 2 crops per year Salinity range
12-20ppt Temperature range 24-30C
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Ration and Temperature
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SF200 Auto(G18) Vs Hand Fed (G17)
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Results
Pond Density SVL Grams Grams/week Yield FCR
Pond (Stocked) SVL Grams Grams/week Yield FCR
Blow-Fed G17 38 76.3 37 1.4 10814 1.54
Blow-Fed G17 -368,000 76.3 37 1.4 10814 1.54
SF200 G18 40 71.1 39.7 1.43 11288 1.42
SF200 G18 -392,000 71.1 39.7 1.43 11288 1.42
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GCMA- Variation in feeding activity, dissolved
oxygen and water temperature over one typical
day.
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Tawee - diurnal variation in feeding activity,
temperature and DO
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Feeding ration switch nocturnal-diurnal due to
temperature
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Spatial Distribution - Feed spread comparison1 h
pond
Shrimp data P.monodon 4 P.monodon 2 L.vannamei 2
Av. size (g) 39 39 20
shrimp 310000 310000 800000
Biomass (t) 12.09 12.09 16

Feeders 4 2 2
Outer radiuss of spreader (m) 10 10 10
Inner radius of spreader (m) 6 6 2
Spread area per feeder m2 201 201 302
Total spread area m2 804 402 603
shrimp per m2 385 771 1326

• vannamei up to x 3.5 times more dense in the
  feeding area
• vannamei reported to utilise entire water column
• rate of intake therefore more rapid with vannamei

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Feed control - Feeder output in relation to wind
and position
Wind Quarter Occurance
N 49 19
E 113 45
S 84 33
W 6 2
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Summary

• Regulates instantaneous feeding rate
• Controls feed delivery rate 24/7
• Feeds to appetite or ration without waste
• Measures feeding activity continuously cf. feed
  tray every 2-3hours.
• System improves FCR growth
• Feed all ponds
• At the best time for the prawns
• Environmental monitoring and alarms for key
  parameters - DO, temperature, power

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Thank you