Seed (aquaculture), Rice field aquaculture, Rice fields, Manuals Oreochromis niloticus

Barman, B.K.

Belton, B.

Haque, M.

Mitra, B.

Roy, S.

English

Research Papers in Economics

 
 
 
 
 
 
Fish Seed Production in Ricefields – 
Participatory Training and Extension Manual 
 
 
 
 
 
Benoy Kumar Barman 
Sattyanarayan Roy 
Mahfujul Haque 
Bilash Mitra  
Benjamin Belton  2
Broodfish Management of Nile tilapia (Oreochromis niloticus; GIFT strain) in Ponds  
 
 
In order to carry out the activities of quality fingerling production of Nile tilapia (Oreochromis 
niloticus) of GIFT (Genetically Improved Farmed Tilapia) strain in rice fields of farmers it is very 
important to maintain and to get necessary supplies of good quality broodfish. In order to 
maintain the quality broodfish of GIFT farmers need to have understanding about the quality 
broodfish and to carry out the following techniques:   
•  To keep large size broodfish considering either original broodfish or largest fingerling 
from current generation produce in their ricefields  
•  During selection of fingerling collect from the rice fields to use for rearing of broodfish it 
needs  to choose healthy,  good shape,  bright color, strong,  well movement, disease 
free, and without any damage in body from their plots  
•  Fingerlings selected should be of similar in shape, collect in large numbers to rear as 
broodfish   
The fingerlings collected then need to be stocked in perennial ponds or ditches after good 
preparation and to carry out regular management. The following activities are needed to be 
carried out for this purpose:  
•  Stocking pond should be free from any shorts of existing tilapia  
•  Before stocking broodfish, pond should be treated with lime (1kg per decimal). Before 
application in the pond lime should be diluted with water at least 24 hours 
•  If  stocked in seasonal ditches which get dry, selected broodfish need to separate based 
on the quality criteria as mentioned earlier and then to re-stock in pond with perennial 
water. If such perennial pond is not available farmer can use relatives or neighbour pond 
or community ponds through negotiation with the pond owners to use the broodfish after 
rearing. 
•  It is suggested that farmers should stock at least 400-500 fingerlings of good quality from 
their ricefields to rear them as broodfish to use in the coming seasons. It may need 100 
or less broodfish for their own plots to produce fingerlings (if the plot size within 30 
decimal) however, the other broodfish they can sell to other farmers. The collection more 
numbers of broodfish is useful to get fish with more diversity useful to maintain good 
genetic quality.   3
•  During management of broodfish the ponds should be fertilize with the application of 
inorganic (urea, TSP) an organic fertilizers as per recommended doses (like the grow-out 
ponds) to keep the water green and use supplementary feeds (rice bran, mustard oil cake 
etc) in required amounts.   
•  It needs to sample the fish regularly ( at least one in a month) to observe the health 
situation of the broodfish and necessary measures need to be undertaken related to 
fertilization and feed management for effective rearing of broodfish to quality.  
•  The brood fish will be transferred into rice field in boro season when plot is properly 
prepared especially with raised dyke and good size ditches well prepared by using lime 
and fertilization. Special care need to be taken to transfer broodfish from the source of 
broodfish to the rice plots to avoid stress  
•  It is useful to stocking sufficient quantity of quality broodfish (i3 broodfish/ decimal) 
maintaining stocking ratio  2:1 for  female and male fish is suggested   
•  Rice plot should be kept well managed in terms of water availability in the ditch, 
connection of ditch with whole rice field, safety from ducks by netting and supplementary 
feeding since after stocking of broodfish in the plot 
 
 
 
 
 
 
 
 
 
 
 
   4
Production of Nile tilapia (Oreochromis niloticus; GIFT) and 
Common Carp (Cyprinus carpio) fingerlings in Ricefields 
 
Introduction 
By stocking broodfish of Nile tilapia (Oreochromis niloticus) GIFT strain and fertilized eggs of 
common carp (Cyprinus carpio) in ricefield during boro season farmer can produce a large 
numbers of large size quality fingerlings. They can sell these fingerings to traders and 
neighbours and/or use for early stocking in own ponds and rice fields for grow-out to get higher 
foodfish production. The farmer can produce enough fish to eat regularly for household 
consumption. In order to produce quality fingerlings of Nile tilapia (GIFT) and common carp 
successfully it needs to follow some basic steps as explained below: 
 
Ricefield preparation 
 
•  Once it has been chosen which ricefield to use it is very important to repair any low dykes 
so that fish cannot escape from the plot when the water level raises. Raise the plot dykes 
to about 1 hand’s (1.5 feet) height above the surface level of the plot. If the dykes are 
already high it may need only to do repairing  (checking for any holes or breakage in the 
dikes)  
 
•  Before stock fish in the plot it needs to make a small ditch where the fish can shelter from 
predators. The ditch should be at least 5 X 5 hands (7.5x7.5 feet) in area, with a depth of 
2.0 hands (3 feet). It is best to make the ditch in a suitable corner of the plot where rice 
productivity is low.  
 
The picture below shows a suitable ricefield. Three of the dykes are high. One of the 
dykes is low and needs to be raised to stop fish escaping when the water level is high. 
The shady corner where the tree is would be a good place to dig the ditch   5
 
 
 
Stocking and feeding of Nile tilapia broodfish 
•  Need to stock Nile tilapia broodfish at a density of 3 fish/decimal from own source or from 
neighbours who reared quality broodfish following good management practices (as 
mentioned above) or from the satellite broodfish rearer who reared broodfish in cages. 
Field trainer should tell farmers when the broodfish are ready to collect and where to 
collect them from. For collection of broodfish from the source and to transport to the 
ricefield plot site for stocking it is better to do using large aluminum patil filled with 
sufficient water early in the morning.  
•  Place the pot gently into the ditch in rice plot. The fish will swim out into the ditch when 
they are ready. 
•  The best period for stocking Nile tilapia in boro rice plot is between mid February to end 
of March  
•  If possible should feed the fish in the ditch every morning and every afternoon so that 
they can grow quickly. Need to feed about one handful of rice bran each time. Observe 
the fish carefully to see whether they eat it all. Other feeds like mustard oil cake also use 
along with rice bran as feed  
   6
 
Stocking Fertilized Eggs of Common Carp 
If there is a pond in the community of farmers which has common carp in it they can also stock 
its fertilized eggs to grow fingerlings in the same rice field with Nile tilapia together. In order to 
do this the following points need to be considered: 
•  Common carp produce eggs mainly between mid February and the end of March 
•  Put a water hyacinth in a pond where there are common carp broodfish. 
•  Observe whether common carp broodfish has exerted their eggs by checking the roots of 
water hyacinth  every few days 
•  Once see eggs collect the hyacinth in a aluminum bowl and need to place it into the ditch 
of the  rice plot 
•  The eggs will hatched out naturally and spawn of common carp will produce in the 
ditches  
•  It needs to apply fine rice bran on regular basis to feed the spawn on regular basis (2-3 
times per day) initially until it become fry, later like Nile tilapia similar sorts of feeds and 
can be done together in the same plot. 
 
Observation of the Ricefield  
In order to get success in quality fingerling production of Nile tilapia (Oreochromis niloticus; 
GIFT strain) and common carp (Cyprinus carpio) it needs for the farming households to do 
regular observation or monitoring of their ricefield. During observation of the rice plots the 
following things need to be considered:  
•  Check the ditch in the ricefield regularly to see whether any fry have appeared. Any 
member of  household (husband, housewife or children) can do this  
•  Check the water level in the ricefield while observing the fry and try to make sure the 
water level doesn’t fall below 5-6 inches. Once fry have appeared they should be able to 
move freely out of the ditch into the rice plot to feed and return to the ditch again to take 
shelter 
•  Normally when a ricefield has fish stocked in it they will eat all of the insects and other 
pests so it is normally not need to use any pesticides. Farmer should always avoid using 
any pesticide in plot after fish have been stocked in it. However, if there is a severe pest 
infestation in the plot farmer can use pesticides bringing all the fish to the ditch and   7
keeping them there for few days until the reaction of pesticides resolved. In order to do 
these farmers must make a strong dyke around the ditch of about 1 foot high. Leave and 
opening about 1.5 feet wide in the dyke so that the fish can swim into it. Drain the plot so 
that all the fish move back to the ditch. Then close the dyke so that they cannot swim 
back into the field. Use the pesticide. Wait at least 3 -5 days after using the pesticide. 
Then make an opening in the ditch so that the fish can return to the field.  The picture 
below shows a ditch with a dyke like this 
 
 
 
Harvesting Fingerlings 
 
•  When the fingerlings in your plot are large size (at least 1.5-2 inch) long they are ready to 
be sold or stocked into your own pond.  
•  Farmers need to talk to fingerling traders and grow-out farmers and inform them that 
fingerlings ready for sale. 
•  Arrange a time with the customers when harvest the fingerlings 
•  Drain the rice plot. As the water level goes down the fish will swim to the ditch 
•  Harvest fingerlings from the ditch by gently using a mosquito net to catch them. Sell the 
larger fingerlings but return any fish less than 1inch long to the ditch so that they can 
grow bigger   8
•  Leave the adult fish in the ditch. 
•  Gradually increase the water level in the rice plot and keep checking the plot and feeding 
the brood fish as you did before 
•  The brood fish will produce more fingerlings which you can also harvest and sell 
•  Fingerings can be harvested about once every three weeks.  
•  Try to keep a record of how many fingerlings you sell, the dates when you sold them and 
how much money you made. 
•  Production of fingerlings is usually highest during the months of May, June and July 
 
Fingerling Production, Income and Household Consumption  
 
•  By stocking of 90 broodfish in 30 decimal (1200m
2) rice plots and by stocking fertilized 
eggs of common carp with water hyacinth in the plot a farmer can able to produce 
>10,000 large size fingerling and can earn at least a net profit of Taka 10000 from the 
plot in addition to the usual production of rice and income from rice.  
•  Farmers able to use good quantity of large size Nile tilapia fingerlings (50-100g) produce 
in their rice plots directly for household consumption of importance to meet up the 
nutrition of the household members especially for minor children and pregnant and 
lactating women as the fish of such small size and delicate age are normally eaten as 
whole fish.  
 
Re-stocking 
 
•  Farmer can keep some of the fingerlings of good quality as broodfish in the ditch or 
perennial ponds (as mentioned in the beginning) after July so that they can produce more 
fingerlings during next boro season using sufficient quantity of broodfish. 
•  If it is not possible to keep own broodfish farmer can purchase such fish from the 
neighbours who maintain the broodfish in their ponds or in cages in ponds for sale. 
 
 
  
 

Fish seed production in ricefields: participatory training and extension manual

http://www.worldfishcenter.org/resource_centre/WF_2781.pdf

Fish seed production in ricefields: participatory training and extension manual

Abstract

Similar works

Full text

Available Versions

Research Papers in Economics