The aim of this study was to compare management strategies for prematuration of the Litopenaeus setiferus male F0 generation through the combination of two factors, culture system and kind of food, measured in terms of sperm quality and the nutritional condition of shrimp. Four treatments were differentiated by culture system and feed (five replicates each). Treatments were clear water commercial pellet (CC), clear water fresh food (CF), biofloc commercial pellet (BC) and biofloc fresh food (BF). At the end of the experiment, survival, spermatic quality, circulating metabolites and prophenoloxidase (ProFO) were evaluated as immune conditions and the oxidative stress enzyme system. Total sperm concentration showed an interaction between culture system and food provided, showing higher values in CC and BF treatments and lower values in CF treatment. ProFO performed an interaction, showing higher activity in CF and BC treatments. Oxidative stress biomarkers showed significant differences (p < 0.05) in PERMANOVA related to the diet, fresh food versus commercial pellet. Data collected in this study show that optimal sperm quality in L. setiferus male prematuration is obtained when shrimp are held in clear water and fed with commercial pellets or maintained in biofloc system and fed with fresh food.

Controlling oxidative stress in shrimps under culture conditions is of vital importance to ensure that males have an optimal physiological status. The use of diets supplemented with vitamins are widely used for this purpose. We evaluated the effects of vitamin C on the metabolic, antioxidant, and immune responses of Penaeus brasiliensisLatreille, 1817 broodstock males under culture conditions. A formulated diet was used as a control (16 mg kg–1 of total ascorbic acid (vitamin C) content) and three diets were prepared with three vitamin C levels: 322 mg kg–1 (Diet A), 628 mg kg–1 (Diet B), and 934 mg kg–1 (Diet C). Triglycerides, cholesterol, glucose, and prophenoloxidase, total proteins, and quantity and type of hemocytes in the hemolymph were determined. We also quantified the antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx) and lipid peroxidation in the reproductive tract. Differentially expressed genes of the immune system, namely those of α-2 macroglobulin (α2M), peneidin (Pen), hemocyanin, prophenoloxidase, and the genes encoding the antioxidant enzymes SOD, CAT, and Gpx were quantified in the tract. Sperm quantity and quality were recorded. In males fed Diet C, the lowest cholesterol values and triglycerides obtained in the hemolymph were not significantly different from those fed the control diet (P &lt; 0.05); those fed Diet C showed the highest amount of hyaline hemocytes, the lowest CAT enzyme activity, and the highest Gpx activity. The immune system genes only showed differences between α2M and Pen; sperm quantity and quality were not affected by diet. The results indicated that Diet C (13.9 g kg–1 vitamin C) was effective for the maintenance of P. brasiliensis broodstock males because it controlled cholesterol and triglyceride levels; there was less CAT activity and less activation of the immune system mediated by hemocytes.