second-most widely cultured prawn species in the world, after only whiteleg shrimp, Litopenaeus vannamei. In 2009, 770,000 tonnes were produced, with a total value of US$3,650,000,000. P. monodon makes up nearly 50% of cultured shrimp alone. The prawn is popular to culture because of its tolerance to salinity and very quick growth rate. However, they are very vulnerable to fungal, viral, and bacterial infections. Diseases such as white spot disease and yellowhead disease have led to a great economic impact in shrimp industries around the globe. They can receive transmitted diseases from other crustaceans such as the Australian red claw crayfish (Cherax quadricarinatus), which is susceptible to yellowhead disease and has shown to transmit it to P. monodon in Thailand. Since black tiger shrimp are susceptible to many diseases, this engenders economic constraints towards the black tiger shrimp food industry in Australia, which is farm-raised. To confront such challenges, attempts have been made to selectively breed specific pathogen-resistant lines of black tiger shrimp. P. monodon has been farmed throughout the world, including areas such as West Africa, Hawaii, Tahiti, and England. For optimal growth, P. monodon is raised in waters between 28 and 33°C. Characteristically for the Penaeus genus, P. monodon has a natural ability to survive and grow in a wide range of salinity, though its optimal salinity is around 15-25 ppt. While in a farm setting, the shrimp are typically fed a compound diet, which is produced in dried pellets. By mixing the diet to have compound feeds and fresh feed, P. monodon was shown to have better reproductive performance. Sustainable consumption In 2010, Greenpeace added P. monodon to its seafood red list – "a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries". The reasons given by Greenpeace were "destruction of vast areas of mangroves in several countries, overfishing of juvenile shrimp from the wild to supply farms, and significant human-rights abuses". Basic research In an effort to understand whether DNA repair processes can protect crustaceans against infection, basic research was conducted to elucidate the repair mechanisms used by P. monodon. Repair of DNA double-strand breaks was found to be predominantly carried out by accurate homologous recombinational repair. Another, less accurate process, microhomology-mediated end joining, is also used to repair such breaks. See also Macrobrachium rosenbergii, the giant freshwater prawn References