![]() The second step lies in pond preparation. If hatchery owners will not let you determine this for yourself, do not buy animals from them. Never buy animals from a hatchery without SPF credentials. In short, never buy PCR-positive animals. Screening pooled animals is helpful, but in the absence of a bio-secure and closed system, it is of dubious value. Positives mean something, and negatives can only be taken as the tests failed to detect the presence of viral DNA. Screening P.L.s is pretty much a useless exercise. If the broodstock are ever in a non-controlled environment during their life cycle, they are not SPF. If not, ask that the hatchery test broodstock held at lower water temperatures. Claims of SPF stock must be supported by history and verifiable audits. ![]() WSSV can become dormant in animals and be undetectable by PCR. Polymerase chain reaction (PCR) testing is not sufficient in the absence of a certified (not just claimed) specific pathogen-free (SPF) system to ensure the virus is not in broodstock. Postlarvae selectionįirst, be selective if you buy postlarvae (P.L.) and smart if you sell them. As this work continues to be investigated under real-world conditions, commonsense steps taken now can lessen the potential impacts of white spot syndrome virus on shrimp-farming operations. More than a dozen groups have cloned structural components of the capsid (the outer protein coat) of the virus into bacterial and other vectors, and shown short-term impacts on the disease vector under controlled conditions. This scientifically fascinating virus is one of the largest ever discovered and has been the subject of dozens, if not hundreds, of publications in peer-reviewed journals. In the last year, white spot syndrome virus (WSSV) once again reared its ugly head. A seven-step program Regular shrimp screening and pond monitoring can help limit the impacts of WSSV.
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