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BMR hatcheries are well equipped with modern sophisticated process systems under highly classified scientific standards to produce high quality Black Tiger (Penaeus monodon) and Scampi seed (M.rosenbergii). The team of highly qualified, dedicated and skilled technical members monitors the process round the clock to produce the quality seed of Tiger Prawn and Scampi. The highly successful methods and the consequent results of mating, hatching, nursing and growing the seed to |
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the required stage are due to the eagle-eyed supervision of our team members. The feed which is totally imported and is perfectly suited to grow the seed from the egg stage to the post larvae stage. These seed at early stage are transferred from green house to the specially designed out door nursery ponds in order to acclimatize them to exposed conditions, thus resulting in excellent, robust post larvae seeds.
Technical process involves the following steps:
1. Site Selection 2. Water Quality Management 3. Maturation 4. Larval Rearing Unit 5. Post Larval Rearing Unit
6. Nursery Unit 7. Daily Monitoring 8. Live feed ( Artemia) 9. Health Care ( Lab)
Proper site selection is one of the key factors for success of any hatchery and it should be feasible and economically viable. Site location must be as near as possible to sea shore and seawater source should be free from agricultural, industrial and sewage pollution. Fresh water should be available in sufficient quantity for daily hatchery operations such as salinity adjustment, cleaning and domestic use. High tension power supply should be available close to the site with generator facility.
2. Water Quality Management
Surface or bore water from the sea is pumped to the slow sand filters which contains various sizes of pebbles, different grades of sand and coal. Chlorination of water is done by bleaching powder or liquid bleaching with proper PPM of concentration and then allowing de-chlorination along with aspirator / aerator. The de-chlorinated water is pumped in to the reservoir and passed through UV before using in the sections.
3. Maturation
Maturation can be done in two methods
a. Gravid
b. Induced maturation
The brooders collected from the sea are acclimated with ambient water conditions
of the hatchery water, and there after the animals are treated with 100 ppm formalin for about half an hour for
disinfection and then transferred to the maturation tanks. If required an
antibiotic dip treatment is also given.
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Feed is distributed in proportionate to various feeds like clams, green
mussels, crab and polychaetes etc., A long handled dip net can be used for removing all
moults, dead animals and unconsumed feed from each tank daily morning and evening.
Induced maturation by unilateral eyestalk ablation means an incision across the eye ball with a razor blade then squeeze out all the contents. Release the females in to the antibiotic solution 20 ppm for about half an hour and then transfer them to the maturation tank. The spawners after proper treatment are shifted to the spawning tank. |
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Each spawning tank with gravid female is to be treated with 10 ppm EDTA (Ethelene Diamene Tetra Acetic Acid) and 4 ppm chloramphenicol. Switch of the lights in the spawning areas and close the room to keep noise level at a minimum. The spawning takes place during night. Good eggs will be greenish granular accumulation at the bottom of the tank. Siphon the egg into a harvesting bucket of 100 mesh. Egg evaluation is carried out after 10 am and allowed to complete development of egg. The eggs may be counted with naked eye against a white background; count three samples and take the average. After spawning the nauplli will hatch out in about 12 hours under normal circumstances.
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4. Larval Rearing Unit The larval phases of shrimp life cycle need an optimum temperature of 28 - 32o C; Nauplii received from maturation are reared in LRT for 13-15 days till they reach PL-5. Nauplii moult repeatedly which passes through 3 zoea, 3 mysis, before they reach PL stage. Entire nauplii stages 1-6 are none feeding, these have embryonic yolk for growth. 5. Tank Preparation After disinfections and drying properly, tanks are filled with seawater passed through 2micron filter bags, up to 50% of the tank volume. Apply EDTA 10 ppm to chealate, |
the dissolved heavy metals pollutants if any. The nauplii 5-6th stage should be acclimatized and can be released slowly at different parts of tank. The temperature can be maintained using titanium rod heaters and also covered with orchid nets; The larval tanks stocking density of 150 / liter is optimum.
Once the N6 stage metamorphosis into Zoea, Chaetoceros spp. algae is fed 6 times a day at 4 hours interval. Feeding schedule can be altered depending upon the feeding behavior; if the feeding is good and Zoea exhibits long faecal strands, feeding can be increased. In Zoea I and Zoea II water is exchanged topped up to maximum.
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Zoea III converted into Mysis has well developed abdomen & carapace. Mysis swims upside down . It has three sub stages of Mysis I, II and III. Mysis larval feeds are phytoplankton and zooplankton. Skeletonema spp. algae are fed 6 times / day at four hours intervals. Artificial microencapsulated and micro particulated Artemia flake, Sea grass powder, Black granules are fed through mesh cloth of 150-200micron. Through Mysis I to Mysis III, 10-15% of water exchange is given using 250micron strainers, for a period of 5-7 hours. PL resemble the adult in the shape. It has well developed pleopods, swimming like an adult, they are reared up to PL6 in larval section. Post Larval are carnivores and are fed artemia 4-6 times/day. |
Micro articulated and Microencapsulated feeds are fed through 100m mesh @ 4 - 7 feeding / day. Water exchange of 50% for PL1 - PL6 is done through 350 strainers over a period of 5 - 7 hours.
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6. Nursery Unit From LRT, PL6 stage are shifted to nursery for further rearing up to PL-20. PL-10 onwards it is acclimatized to lower salinities. Tanks are filled with filtered and treated sea water upto 50% of tank volume. Artificial feeds like OSI flake, Higashimaru 0,1,2 are used to feed through 100u mesh . Stocking is done at a density of 30 nos/ltr. The seed in the out door nursery are accustomed to fluctuation in temperature and other water parameters. This technology gives better survival to the farmers. |
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Artemia is fed 4-5times a day and supplementary feed of Micro particulated early PL feed and late PL feed are fed 7-8 times/day squeezed to through 100micron cloth.
7. Daily Monitoring
During the entire cycle operations, daily schedule of work has
to be strictly followed. The physical examination of culture facility like tank
condition and aeration is watched at frequent intervals.
Daily observations includes the following:
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Feed in the media i.e., algal, artificial and Artemia -
External attachment to the animal
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Feeding efficiency through gut observation
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Moulting
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Activity and behavior of the larvae
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Population estimation.
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8. Live feed Culture a. Algae Three to four spp. of algae is cultured and maintained to feed the larvae at various stages. The sustainable methods of batch culture is practiced. The tissue culture from the agar slands are innoculated to 10ml test tube medium once in a month. The subsequent cultures like 10ml to 100ml and 100ml to 1000 ml.. are done once in a week interval. Further cultures like 1 to 5lts. and to 100lts cylinders are done once in two days and the out door culture daily basis. Species like Chaetoceros, Skeletonema and Tetraselmis are normally maintained.
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b. Artemia
Artemia also known as "Brine shrimp" are found in high saline ( 150-200 ppt) waters. The nauplii of which is extensively used as live food. At extreme conditions of high salinity, temperature and low level of oxygen, the embryo undergoes encystment. The embryo can remain dormant in the cyst for more than an year when the environmental conditions are favorable on dehydration at 28-35 ppt and 28-34oC with aeration, the nauplii will hatch out from cyst within 24-30 hours.
The known weight of the cyst stocked in a cylindrical FRP tank 400-500 liters capacity with transparent conical bottom and a lid natural sun light or artificial tube lights of 2,000 lux need throughout the hatching
The cysts should be thoroughly disinfected with 200 ppm of bleaching which partially encapsulated for 15 minutes. then washed with fresh water till the chlorine gas escapes. stocking is done at a density of 1-2g / liter and usually the harvest of fresh nauplii is made at 18 hours and at 24 hours .
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Stop aeration remove the stand pipe and cover the tank with lid. Arrange a 60w bulb at the transparent bottom to attract the nauplii towards the light there by facilitating separation of the nauplii floating cysts. The drain valve in the bottom is opened slowly to collect the nauplii using a 100micron net. The harvested nauplii is thoroughly washed in freshwater and is filtered through 227micron mesh to remove any unhatched cyst. The harvested nauplii is released into the 100 liter capacity tank for estimating by tracking sample volume of 1 ml and counting. By this method, calculate how much millions of nauplii harvested and their hatching percentage |
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