Blood metabolites and hemocyanin of the white shrimp, Litopenaeus vanaamei: the effect of culture conditions and a comparison with other crustacean species

Abstract

Oxyhemocyanin (OxyHc), blood protein, glucose, acylglycerol (AG), and lactate of Litopenaeus vannamei juveniles were investigated. Statistical analyses were done on baseline values for each metabolite and on OxyHc from shrimp cultured in outdoor (20-m(2) ponds) and indoor (90-1 tanks). The values obtained were compared with blood metabolites reported in the literature for L. vannamei maintained under similar conditions. Normal distribution was only found for samples from indoor shrimp. The distribution values for blood metabolites from shrimp cultured in outdoor ponds and indoor tanks were right or left skewed. OxyHc, blood proteins, and glucose levels were higher in shrimp cultured in outdoor ponds than those observed in shrimp maintained in indoor tanks. These differences were attributed to availability of live food in outdoor culture ponds. The OxyHc/protein ratio showed that 60% of blood protein is OxyHc in outdoor-cultured shrimp and was lower than in indoor-cultured shrimp, and this ratio was lower than that found (97%) in indoor-cultured shrimp. The type of food was identified as a dominant factor affecting blood metabolites. AG in outdoor-cultured shrimp was significantly lower than that observed in indoor-maintained shrimp. Blood lactate concentration of shrimp was not affected by the culture conditions. The blood levels for protein, glucose, and lactate reported here are similar to those reported previously for other crustacean species, indicating that these can be used as a reference for evaluating the physiological status of L. vannamei. When we compared the OxyHc, blood protein, glucose, and lactate levels of L. vannamei juveniles with other crustacean species, we observed that crabs, lobsters (low-activity species), and closed-thelycum shrimp species (mean-activity species) had lower values in comparison to those observed in open-thelycum shrimp species, including L. vannamei juveniles. Possibly the blood metabolites and OxyHc could be reflecting the morphological and physiological adaptation of crustaceans, because these metabolites will depend on energetic demands.