World Aquaculture 67 Specific pathogen free shrimps: Their scope in aquaculture Debtanu Barman1, Vikash Kumar2, Suvra Roy2 and Sagar C Mandal3* Shrimp farming underwent a major expansion mainly in Ecuador, the Philippines, Thailand and Indonesia during 1980’s. In each country, production continued to increase in the 1990s and is now experiencing problems with many diseases. Reports are that specific pathogen-free (SPF), or IHHN virus-free Penaeus vannamei will be well accepted in Ecuador because SPF stocks have been demonstrated to be effective against the runt deformity syndrome. The captive maturation infrastructure required to propagate these stocks is already in place and the demonstrated efficacy will result in higher yields and higher value crops. In addition, the ability to produce a continuous, year-round supply of high quality nauplii will increase the efficiency of grow out sectors and result in lower costs and higher profit margins for shrimp farmers. Specific pathogen-free P. monodon have not yet been studied under production conditions in Asia. However, shrimp farmers in Southeast Asia have shown an interest in pursuing the development of an SPF P. monodon stock. The long-term viability and market value of SPF P. monodon post larvae (PL) will be determined by their performance in commercial production. Therefore, the process of identifying and isolating SPF P. monodon broodstock should begin as soon as possible so that their performance in commercial production systems can be evaluated. Specific Pathogen Free (SPF) Animals The SPF animals are special stock of animals that are kept in SPF facilities under a rigorous monitoring system. These animals are subjected to sensitive and accurate diagnostic methods. They are repeatedly bred under controlled conditions to maintain their freedom from specific pathogens and the SPF designation itself is tested on a regular basis. The SPF animals are not innately resistant to the specified pathogens or infections, although they can possibly be developed as specific pathogen resistant (SPR) species. They are not produced to provide either superior genetic stock or improved culturing attributes, such as faster growth. Specific pathogen-free shrimp are maintained in highly biosecure facilities and have been routinely checked and free of specified pathogens. There is no single internationally recognized SPF list, although it is generally agreed that SPF shrimp must be regularly tested for and be declared free from the pathogens. Specific Pathogen Resistant (SPR) shrimp are those that are not susceptible to infection by one or several specific pathogens, and Specific Pathogen Tolerant (SPT) shrimp are those that are intentionally bred to develop tolerance to disease caused by one or several specific pathogens. There are lines of commercially available L. vannamei in the USA that are SPF and SPR, but only to Taura syndrome virus (TSV). These shrimp are not necessarily any more resistant to other viruses than any other shrimp. This process has occurred for the production of domesticated lines of L. vannamei and L. stylirostris broodstock throughout the America and now moves some Asian countries like China, Thailand, Indonesia and Malaysia with L. vannamei. In fact, the advantages that the use of such animals offers has in the past four years, led to L. vannamei becoming the world’s most important cultured shrimp species. Advantages of Using Domesticated and SPF/SPR Stocks: • Ready, year-round availability of disease-free broodstock • Ability to be selected for desirable traits such as fast growth rate, disease resistance and, hence, high survival, good FCR and increased production and productivity • Reduced use of chemotherapeutants • Better adaptability of domesticated shrimp to captive environments, leading to reduced stress and better mating and reproductive success • Increased traceability of the origin of stocks, their past performance and future potential Status of SPF around the World Currently, there are a number of programs aimed at producing domesticated stocks of disease-free P. monodon broodstock; these include projects in Hawaii, Thailand and Australia. Recent claims by the private sector are on the commercial availability of domesticated P. monodon in Thailand and Hawaii. Private, government and academic institutional cooperative development of SPF P. monodon broodstock domestication also began in Australia in 1997. Although significant success has been achieved, stocks from the program are not yet commercially available. Status of SPF in India The development of SPF stocks is probably a viable longterm solution for India. The marine product export development authority (MPEDA) has already begun efforts in SPF development. Two entrepreneurs have been permitted to import 500 SPF L. vannamei, while a proposal to import 10000 P. monodon broodstock has been approved by the government. A consultant for transfer of technology on SPF shrimp has been identified and he has already prepared a prefeasibility report. The site for the nuclear breeding center has also been
RkJQdWJsaXNoZXIy MjExNDY=