Aclimatación Camarón A Baja Salinidad

SRAC Publication No. 2601

June 2004

PR

VI

Acclimating Pacific White Shrimp, Litopenaeus vannamei, to Inland, Low-Salinity Waters
D. Allen Marine shrimp are traditionally cultured in coastal or estuarine waters. However, inland culture is now being done in many countries. In the United States, farmers in Alabama, Arizona, Florida, Illinois, Indiana, Michigan, Mississippi, SouthCarolina and Texas have successfully reared marine shrimp using low-salinty groundwater. The Pacific white shrimp, Litopenaeus vannamei, is the species of choice of the shrimp farming industry in the western hemisphere. The species is found in waters with a wide salinity range (1 to 40 ppt). The high tolerance of L. vannamei to low salinity and the year-round availability of healthy post-larvae (PL)make this species an excellent candidate for inland farming. There is little published information about the growth and survival of this species in well water or inland surface water. Some of the first reports were from West Texas, where this species was successfully produced in earthen ponds (86.7 percent survival). The shrimp grew from 1.2 g to about 20 g in 120 days Davis1, Tzachi M Samocha2 andC. E. Boyd1 at a stocking density of 25 know how to acclimate shrimp to shrimp/m2. There are also reports the low-salinity water. Once the PL of super-intensive culture (109 or juvenile shrimp are acclimated shrimp/m2) in earthen ponds (0.1 to local conditions, the farmer ha) in the Sonora Desert of must deal with typical production Arizona, with production as high issues such as feeding,maintainas 12,000 kg/ha in low-salinity ing water quality (including ionic groundwater of 2.0 ppt. profiles), and managing blooms of undesirable algae. Because of variations in water and soil, some farmers have had probWater suitability lems rearing this shrimp while others have been successful. In Before culturing any species, one Thailand, where water for inland must evaluate the suitability of theshrimp culture is prepared by water through both chemical and diluting brine solution (100 to 250 biological tests. The ionic composippt salinity) from coastal, seawation of water appears to be more ter evaporation ponds with fresh important than the salinity. It has water, most ponds have ionic conbeen demonstrated that single salt centrations similar to that expectsolutions of sodium chloride are edfor seawater diluted to the not suitable for shrimp culture at same salinity. However, in any salinity, even though in seawaEcuador and the United States, ter the ions most important in where shrimp are cultured mostly osmoregulation are chloride and in groundwater, many ponds have sodium. Current research suggests much lower concentrations of that if the salinity is adequate, calpotassium andmagnesium than cium (Ca), potassium (K) and expected in diluted seawater. magnesium (Mg) are the most important ions for shrimp surResearchers have been working to vival. Any of these ions can be limidentify reasons for differences in iting, but often a lack of K is the survival and growth among most important factor affecting farms, and to develop strategies shrimp. It should be noted that foracclimating and producing although high levels of Ca also shrimp under various conditions. seem to be necessary, the ratio of The first thing a farmer must Ca:K, which is about 1:1 in seawadetermine is whether or not his ter, may also be important. In water is suitable for shrimp culwaters where the Ca:K ratio is ture. If it is suitable, he must

1Department of Fisheries and Allied

Aquacultures,Auburn University 2Texas Agricultural Experiment Station, Shrimp Mariculture Research Facility at Corpus Christi

high, the addition of K to reduce this ratio has been helpful. Unfortunately, there are many interactions between minerals in low-salinity waters so there is no clear rule-of-thumb. In general, water is suitable for shrimp culture if: • salinity is above 0.5 ppt; • levels of Na, Cl...