So where are so called jumbo prawns (really shrimps) of the genus Macrobrachium found? Macrobrachium rosenbergii is indigenous to the tropics and sub-tropics such as Southeast Asia and the Western Pacific as well, but humans have greatly expanded the range of Macrobrachium distribution through cultivation and research projects. Nowadays, any environment which reproduces the South Asia / Southeast Asia conditions and supports jumbo prawn culture may be found to have a budding jumbo prawn farmer making an effort to commercialize the species there.