Engormix/Aquaculture/Technical articles

Keys to Shrimp Seed Selection

Published on: 11/21/2019
Author/s : Nancy Yang, Lachance
Find the right shrimp seed farm
1. Investigate the qualifications of the shrimp seed farm. The scale, capital strength and reputation are critical factors for shrimp seed farm selection. Production license is a must for a good shrimp seed farm, which indicates the technical capability, management level and the quality of shrimp seed.
2. Don’t select the shrimp seeds transported from one farm to another because such shrimp seeds are likely to suffer secondary infection, which may cause decreased survival rate.
3. Don’t follow one single brand or farm blindly. Every farm has good shrimp seeds as well as bad shrimp seeds. The most popular farm may have its own disadvantages e.g. overuse of parent shrimp, which increases the possibility of infections. Furthermore, you may lose the best business opportunity when you are waiting for the shrimp seeds from the so-called popular farm.
4. Do preliminary inspection on the shrimp seed. Negotiate with the farm owner and decide on the pond number, date for seed production, salinity and size of shrimp seed. Observe the state of shrimp seeds living in the water. If the quality of those shrimp seeds is unsatisfactory, then quit them and consider other choices.
Keys to Shrimp Seed Selection - Image 1

Investigation on the seed production process
1. Parent shrimp should be big, healthy and preferably imported from other countries. The first-generation shrimp seeds bred with imported high-quality parent shrimp have many advantages such as fast growth and high survival rate, which can grow to be of large size shrimp, uniform in body shape and high in production capacity. In contrast, local parent shrimp is small and inbreeding problem usually occurs. As a result, the shrimp seeds bred with local parent shrimp are not the best choice.
2. Water temperature should be well controlled for shrimp seed breeding. Shrimp seed grows faster in higher temperature water within proper temperature range, 30-32?. Do not select the shrimp seeds growing in the water higher than 32?, which grow fast but poor in health.
3. Cultivation cycle of shrimp seed should be around 20 days otherwise the feed intake and growth of the shrimp seed may be abnormal if the cultivation cycle is too long or too short.
4. Survival rate of the same batch of shrimp seeds should be high enough only by which the quality of shrimp seeds can be guaranteed.
5. Feed of shrimp seed includes rotifer and fairy shrimp. Use good quality feed when breeding shrimp seeds to ensure the health and survival rate.
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Check the health and vitality of shrimp seeds
1. Firstly, observe the liver of shrimp seed. Observe the color of the shrimp seeds in the whole pond. If two or more colors are found in the same batch of shrimp seeds, it can prove that the liver of shrimp seed is not qualified. Observe the liver color of smallest shrimp seeds, if no red liver is found, the quality of the shrimp seeds is good. That’s why some farm prefer to use red color feed, which may cover the liver disease of the shrimp seeds. In addition, if white points are found in the surface of the liver, do not select such shrimp seeds.
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2. For a 0.8-1cm shrimp seed, its intestinal track should be thick and black (clear intestinal track to the tail) and 20%-30% of shrimp seeds create shaped feces in the water. If there is food in the stomach but no feces in the intestinal track, such shrimp seeds are likely to be influenced by the change of water quality and probably be infected with disease.
3. Vitality is anther critical standard for judgement of the shrimp seed quality. If the shrimp seeds are vibrant and healthy, they will lie on the wall of the water ladle, after being caught by a water ladle (there should be not too many shrimp seeds in the ladle). If those shrimp seeds keep swimming in the water, it proves that their anti-stress ability is low and they cannot get used to the new environment very well. Most of the people think it indicates the vitality of the shrimp seeds, but actually it is not. Shake the water ladle and make the water swirling in the ladle. Good shrimp seeds will separate immediately after being gathered in the center and then lie on the wall of the water ladle after overcoming the resistance of water flow.
In the pond, shrimp seeds with different vitality are spread in various locations.
Usually the good shrimp seeds gather in the walls or at the bottom of the pond. Those shrimp seeds flow with the water flow are the worst. For some outdoor farms, the shrimp pond is covered with a tarpaulin, leaving only a narrow gap to allow the sunlight in. Due to its phototaxis, the shrimp seeds with good vitality will gather in the area where the sunlight reaches and we can get shrimp seeds from those areas.
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4. Observe the foam on the water surface in the pond. If most of the foam is white and transparent, it indicates that the water is clear and no food organism is left, which represents the good quality of shrimp seeds. If the foam is red, check whether there is too much contamination on the walls. The contamination may be caused by overfeeding. Smell if there is odor. If it is smelly, the shrimp seeds may be poisoned.
5. White seeds are dead seeds. If dead seeds are found when catching shrimp seeds with a water ladle, do not select the shrimp seeds in this pond. The reasons for dead seeds include diseases and improper farm management e.g. overfeeding will cause chronic ammonia nitrogen poisoning.
6. One day before collecting the shrimp seeds from the farm, go to the farm and turn off the lights of the workshop and keep the shrimp pond in dark for at least 15 minutes. Observe whether there are shining points in the pond for 2 minutes. If there are shining points, it indicates that there are photogenic bacterium, which is the main cause of EMS (Early Mortality Syndrome). The survival rate will be less than 10% if there is photogenic bacterium in the water.
A simple method to judge the quality of shrimp seed
1. Prepare one basin with clean sea water and place 100-200 shrimp seeds in the basin. Stir the water slowly to form small water flow and when the water flow becomes slow, observe the distribution of shrimp seeds. Those shrimp seeds at the bottom or near the wall of the basin are good shrimp seeds while those follow the water flow are unqualified shrimp seeds.
2. Place several shrimp seeds in a wet towel which has been twisted and wait for 10 minutes. Then remove those shrimp seeds back to the pond. If all of those shrimps survive, it proves that they are good shrimp seeds. If the survival rate is low, the shrimp seeds can be regarded as unqualified.
3. Try the shrimp seeds in the water where the shrimp seeds grow. After one day, the survival rate of good shrimp seeds should exceed 95%.
Keys to Shrimp Seed Selection - Image 5
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