Fin fish culture systems.ppt commercial important

finfish culture

1. FINFISH CULTURE
SYSTEMS

2. •ThemilkfishChanoschanos-onlyspeciesofthefamilyChanidae
•Doesnotformacapturefisherysignificance
•ImportantinlargescalefarminginSoutheastAsia
•CultureoriginatedinIndonesiaandspreadtothePhilippinesandTaiwan
•MarinefishoftheIndianandPacificoceans
•Theyoungonesspendtheirlifeininshoreestuarineareasandascendrivestothe
freshwaterzones
•Theyarehighlyeuryhalineandcanliveinfreshtohyper-salinewaters
•Toleratetemperaturefrom15-40
o
Cbuttheoptimumisbetween20and33
o
C

3. Culturesystems:
•Includesnurseries,andrearingponds
•Usually-monoculturesystems;canalsobepolyculturedwithmulletsandshrimps
•Themoreimportantfarmingsysteminfreshwaters-penfarming-inlakesinthe
Philippines(LagunadeBayandLakeSampaloc)

4. Frycollection:
•Milkfishdonnotmatureandspawnnaturallyincaptivity
•Spawnnearthecoastandlarvaeoccurperiodicallyalongthesandycoastsandin
theestuaries-collectedfromwild
•Gears-differenttypesofdipnets,suchasthetriangularscissornetinthe
PhilippinesandthescoopnetinTaiwan
•Dipnetssuitedforareaswithlargeconcentrationsoffry
•Seinenets,dragnetsandtrapsare

5. •Intraditionalmethods-frycongregatingdevices-rockwallsorlurelinemadeof
fibreropesstrungwithplaitedstripsofcoconutandbananaleaves
•Powerboatsarealsousetotowseinenetsandscoopnets.Thisextendsthearea
ofcollectiontoofftheimmediatecoastandismoreefficient.Thebestcollections
aremadeatthecreekmouths.
•Thefryaccumulatedin2-6m³shadedconcretetanksnearthecollectionsitein
about10cmofwateratadensityofabout40,000frypertank
•Fryarethenpackedinpolythenebagfilledwithwaterandpureoxygenanddeliver
tofrydealers
•Dealersholdthefryincementtanksbeforesellingtothefarmers

6. Artificialpropagation:
•SincethesupplyfromwildmaynotbesufficienttosupplythedemandtheAQDofthe
SEAFDECinthePhilippineshasdevelopedtechnologytoproducemilkfishinhatcheries
•Broodfisharerearedincapturedfromthewildandrearedforseveralyearsincaptivity
sincethisfishmaturesattheageof5-7yearswhenitisatleast3.5kgweightand60cm
inlength
•ThefishareinducedtospawnimplantationofLH-RHcholesterolpellets

7. •Eggsarecollectedwithplanktonnetsandhatched
•Frystartfeedingin2days
•Theyaremaintainedingreenwater,fedsmallrotifersandfertilizedoystereggs
•After10dayslivefeedisreplacedbycommercialartificialfeed
•Atadensityof1500t6000/m2,twotothreeweeksafterhatchingfryreach1.5cm.

8. Grow-out
1.Fish ponds: coastal low lands/mudflats
•The land should between average sea level and 45 cm above sea level
•The elevation should be such that ponds can be dried completely
•Soil should be loamy or siltyloam.
•The farm consists of production ponds, wintering ponds, nursery ponds and water
canals
•Production ponds: the area of the production ponds is 3 –8 ha, their long sides at
90
o
to prevailing wind
•Bottom is flat with a drop of 3 cm per 100 m
2
•Trenches converging at sluice gates should be made at the bottom
•Water depth should be maintained at 45 cm.

9. 2.Wintering ponds:Necessary when temperature falls ‹15 °C
•Comprise 2-5% of the farm area.
3.Nursery ponds:18 to 25m wide and 20 cm deep along the length of the
production ponds. They consist of 2-3% of the farm area.
4.Water canal: Constructed to supply and drain water to and from the ponds.
•Connected to sluice gates and can be up to 15 m wide

10. Pondpreparation:
•Decomposingalgaearerakedandspreadevenly
•Dykesarerepairedandallleaksplugged
•Pondsaredriedtogetridofpestsandtooxidizepondsediments
•Finemeshnetsareinstalledintheinletstopreventunwantedorganismsfrom
enteringtheponds
•Naturalfood,lablabisgrownatthebottom
•Applyagriculturallimeat1tonperhaandchickenmanureat2tonsperhaon
moistpondbottom
•Aweeklaterapplyammoniumphosphateat20kgperhaandureaat10kgperha
pond manuring

11. •Theamountsofinputsmaybechangeddependingontheproductivityandpond
history
•Aslablabgrows,increasewaterdepthto30cm
•Fertilizersagainaddedafterbiweeklywaterexchangeatthesameorhalfthebasal
rate
•Fryofabout5mgsizearestockedattherateof75to100perm2.Theyare
harvestedwhentheyreach5-10g
•Growoutpondsaresimilarlypreparedatstockedwithfingerlingsofsize5-10gat
therateof7000-8000fingerlingsperha

12. •Water management:
•30cm water level is maintained for first 30-40 days with lab lab
•It is increased to 50-100 cm when fish grow bigger and supplemental feeding starts
•Pumping may be necessary to keep the pond water at a higher level than outside
•Monitor dissolved oxygen at 6-8 AM and 2-4 PM
•Aeration becomes necessary if oxygen levels drop to 1 ppm.

13. Supplementaryfeeding:
•Thefishfedareamixtureofricebranandoilcakesattherateof2-3%ofthebody
weight
•Feedingshouldbeavoidedonovercastdaysandwhenoxygenlevelsfallbelow2
ppm
Harvesting:
•Overwinteredfryof100to150greachmarketablesizeof300to450gineight
weeks
•Newfryreachmarketsizein5months
•After2monthsofstockingfishcanbepartiallyharvestedbydragginggillnets
•Finalharvestiscarriedoutwhenallthefryreachmarketablesize
•Aproductionof2000-5000ka/ha/yearcanbeexpectedfromsemi-intensive
cultureofmilkfish