A standardized comparison of semi-intensive pond culture of freshwater prawns Macrobrachium rosenbergii at different latitudes: production increases associated with lower water temperatures

摘要: Abstract This study was conducted to evaluate the effects of different ambient water temperatures on growth and population structure freshwater prawns raised under standardized culture conditions. Juvenile averaging 0.26 ± 0.14 g were stocked into seven 0.04 ha ponds at two sites. Three located in Kentucky (KSU:latitude 38 °12′) with seasonal 24–26 °C. Four Mississippi (MSU:latitude 33 ° 28′) a average approximately 30 Prawn stocking, sampling, harvest dates identical both locations. single source harvested from same nursery tank for stocking The diet used sites production run stored refrigerated Prawns fed twice daily according computer generated feeding schedule. Beginning 8 weeks prior harvest, sampled also individually identified sexual morphotype. At (117 days after stocking) all counted, morphotyped, weighed. weights higher more northerly site samples 42 post-stocking. When 64 post-stocking (5 August) no sexually mature male or females found. Mature morpho-types first captured Day 83 sampling (25 August). In 106 (16 September), there significant differences ( P > 0.05) numbers three morphotypes between However, among significantly fewer prawn survival (83%), weight (35 g), feed conversion (2.3). Production greater ≤ 0.01) KSU (1261 kg −1 ) than MSU (1091 largely reflecting some slightly survivals. Differences proportions sizes female probably indicate delayed maturation site, prolonging somatic which normally ceases when food energies are redirected reproductive activities.