Effects of adaptation to laboratory conditions on growth, molting, and food consumption of juvenile Farfantepenaeus duorarum (Decapoda: Penaeidae)

Growth patterns and biochemical analysis at laboratory conditions (temperature 28°C, salinity 22) were analyzed in juveniles wild pink shrimp, Farfantepenaeus duorarum (Burkenroad, 1939), caught in the Gulf of Mexico compared with cultivated (F2) organisms. Shrimp were maintained for 55 days to monitor the molt frequency and weight gain over time. We determined the frequency of molting and wet weight gain per day over the experiment time. Wild shrimp had an average molting frequency of 10 ± 2.03 days with an increase in wet weight of 0.024 ± 0.001 g day−1; whereas cultivated shrimp had an average frequency of 11 ± 2.15 days and a growth rate of 0.084 ± 0.002 g day−1. Osmotic capacity was determined in wild shrimp at 154.85 ± 73.47 mOsm kg−1 and for cultivated at 128.67 ± 42.24 mOsm kg−1. Total protein concentration was 35.15 mg ml−1 for wild shrimp, while values for cultivated shrimp were significantly different at 112.22 mg ml−1 (ANOVA; p < 0.05). Also, an experiment was conducted to determine the amount of food consumed before and after ecdysis in wild and cultivated shrimp. No significant differences were found in the food consumption (F = 0.220, p = 0.641) between groups before and after ecdysis. We determined that food consumption rate fell by 30% during molt and that feeding did not cease when ecdysis occurs.