PLs ready for stocking in nursery ponds, biofloc tanks, or production ponds.
Setting aside the details about actually building the farm and all of the required infrastructure, the process is as follows.
One must start with a source of baby shrimp. These are called post larval shrimp or PLs for short. Shrimp go through a series of larval stages after the eggs hatch before they molt into PLs. Shrimp are invertebrates with their skeletons, consisting of a polymer called chitin, on the outside of their bodies. They must shed or molt this to grow. As the post larval shrimp molt (typically daily in hatchery tanks) they are designated by the days post larval development. Secondary gill development, essential for the ability to osmoregulate, is monitored and typically when the animals have the required level of development they are ready for stocking into ponds. This ranges from PL8 on up. The photo above shows high quality PLs ready for stocking.
Some things that are crucial during this stage of production:
Source of broodstock.
Wild broodstock are still used in some parts of the world despite the practice being widely panned as not being sustainable, carrying with it a high risk of disease and in general a poor practice. Most farmed shrimp are produced from captive broodstock. These fall into several categories ranging from the highly biosecure to the flagrantly non-biosecure. Biosecure stocks are necessary to minimize the potential for disease problems on the farm.
There are genetically improved animals commercially available for P. vannamei. Genetics programs range from the very small to the huge. The safest source of broodstock is from the few companies that have nuclear breeding facilities. This means that the animals have been held in isolated indoor, bio-secure environments for multiple generations. They are specific pathogen free (SPF) and in some cases have shown tolerance against some diseases (SPT). While some companies claim animals are resistant this is not usually accurate. Few strains are not susceptible to pathogens at some levels and the role(s) of stressors in stress filled production systems is not widely appreciated. Field data is not a good measure of susceptibility. Controlled lab studies are needed to verify that the animals are showing some degree of tolerance to the pathogen(s) of interest. Unfortunately this does not mean that in the field the animals will be any less likely to fall ill.
When you use broodstock that are not from nuclear breeding centers and that have been produced outdoors, regardless of test results, they can no longer be considered SPF. Unfortunately far too many farmers fall victim to forged certificates or simply do not understand what this really means. They buy based on price and relationships not on science based assurances of quality. PCR results for some viruses are not reliable.
One must start with a source of baby shrimp. These are called post larval shrimp or PLs for short. Shrimp go through a series of larval stages after the eggs hatch before they molt into PLs. Shrimp are invertebrates with their skeletons, consisting of a polymer called chitin, on the outside of their bodies. They must shed or molt this to grow. As the post larval shrimp molt (typically daily in hatchery tanks) they are designated by the days post larval development. Secondary gill development, essential for the ability to osmoregulate, is monitored and typically when the animals have the required level of development they are ready for stocking into ponds. This ranges from PL8 on up. The photo above shows high quality PLs ready for stocking.
Some things that are crucial during this stage of production:
Source of broodstock.
Wild broodstock are still used in some parts of the world despite the practice being widely panned as not being sustainable, carrying with it a high risk of disease and in general a poor practice. Most farmed shrimp are produced from captive broodstock. These fall into several categories ranging from the highly biosecure to the flagrantly non-biosecure. Biosecure stocks are necessary to minimize the potential for disease problems on the farm.
There are genetically improved animals commercially available for P. vannamei. Genetics programs range from the very small to the huge. The safest source of broodstock is from the few companies that have nuclear breeding facilities. This means that the animals have been held in isolated indoor, bio-secure environments for multiple generations. They are specific pathogen free (SPF) and in some cases have shown tolerance against some diseases (SPT). While some companies claim animals are resistant this is not usually accurate. Few strains are not susceptible to pathogens at some levels and the role(s) of stressors in stress filled production systems is not widely appreciated. Field data is not a good measure of susceptibility. Controlled lab studies are needed to verify that the animals are showing some degree of tolerance to the pathogen(s) of interest. Unfortunately this does not mean that in the field the animals will be any less likely to fall ill.
When you use broodstock that are not from nuclear breeding centers and that have been produced outdoors, regardless of test results, they can no longer be considered SPF. Unfortunately far too many farmers fall victim to forged certificates or simply do not understand what this really means. They buy based on price and relationships not on science based assurances of quality. PCR results for some viruses are not reliable.
