The potential for Macrobrachium rosenbergii culture in arid regions

Abstract

Recent declines in the availability of large marine shrimp reinvigorated the market for the freshwater prawn Macrobrachium rosenbergii. Simultaneously, pressures to find more lucrative and water efficient crops are increasing in arid regions. The integration of a highly valuable crop such as Macrobrachium with irrigated agriculture could be of benefit to arid land farmers. Using a specific farming region in Arizona as a model of arid land systems, the objectives of my research were to: (1) Determine if the physical conditions for prawn culture occur in Arizona. (2) Investigate the feasibility of inland larvae culture. (3) Raise to maturity and spawn M. rosenbergii. (4) Assess the utility of a new species evaluation protocol. To meet these objectives, I reviewed physical conditions in Central Arizona and compared them to known requirements for culture of M. rosenbergii, developed a model larvae culture method and stocked postlarvae from the larvae culture experiments into ponds where they could grow to maturity and spawn. After spawning, the larvae were collected and the fecundity of the adult females determined. My results suggest M. rosenbergii likely can be cultured seasonally in ponds filled with surface water within the representative region. Constraints to culture include high source water pH, hardness, alkalinity, contaminants and low winter water temperatures. Larvae culture is possible within the representative region. However, successful mass culture will require refinement of techniques used in my study. Constraints to culture include high ambient pH of surface waters, periodic high hardness and alkalinity levels and low winter temperatures. Improved filtration techniques in the incubator and a consistent availability of Artemia for food are also issues of concern. Prawns hatched and grown in Arizona spawned readily, were as fecund as other cultured stocks and produced viable larvae up through stage 2. The protocol I used was appropriate for evaluating a species for aquaculture at a new location. Overall, M. rosenbergii shows potential as a candidate for integration with irrigated agriculture systems within arid farming regions.