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Abstract:
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Aquaculture is a form of agriculture that involves the propagation,
cultivation and marketing of aquatic plants and animals in a controlled
environment (Swann, 1992). After growing steadily, particularly in the last
four decades, aquaculture is for the first time set to contribute half of the fish
consumed by the human population worldwide. Given the projected
population growth over the next two decades, it is estimated that at least an
additional 40 million tonnes of aquatic food will be required by 2030 to
maintain the current per capita consumption (FAO, 2006). Capture fisheries
and aquaculture supplied the world with about 110 million tonnes of food fish
in 2006. Of this total, aquaculture accounted for 47 percent (FAO, 2009).
Globally, penaeid shrimp culture ranks sixth in terms of quantity and second in
terms of value amongst all taxonomic groups of aquatic animals cultivated
(FAO, 2006). In places where warm-water aquaculture was possible black
tiger shrimp, Penaeus monodon became the preferred variety of shrimp cultivar owing to its fast growth, seed availability and importantly due to high
prices it fetches (Pechmanee, 1997). World shrimp production is dominated by
P.monodon, which accounted for more than 50 % of the production in 1999
(FAO, 2000). In the last few years the whiteleg shrimp, Litopenaeus
vannamei, has replaced P.monodon in many countries. Indian shrimp culture is
dominated by P.monodon with the East Coast accounting for 70% of the
production (Hein, 2002). Intensive culture, apart from other problems, results
in enhanced susceptibility of the cultured species to diseases (Jory, 1997),
which in fact have become the biggest constraint in shrimp aquaculture (FAO,
2003). |