Efecto del prebiótico inulina y el alga verde Ulva lactuca en el crecimiento, supervivencia y sistema inmune de Litopenaeus vannamei, cultivado en condiciones experimentales

Abstract

The culture of Litopenaeus vannamei is a very important productive activity in northwestern Mexico. In this research we evaluated the prebiotic inulin and the green algae Ulva lactuca in the growth, survival and immune system of L. vannamei, cultured in the laboratory. In the bioassey were used plastic tanks with 80 L of sea water, constant aeration and 10 shrimp/tank. Inulin and macroalgae were added to the feed (Camaronina®, 35% protein). Feeding was done ad libitum twice a day, daily cleaning was done and determination of physicochemical parameters every 3 days. Water quality and weight determination were carried out at the beginning and end of the bioassay. We determined the specific growth rate. The three bioassays were performed in triplicate. Bioassay 1 (62 days, 1.1 ± 0.08 g): I) control diet (Camaronina); II) Camaronina + 1.25 g inulin/kg feed; III) Camaronina + 2.5 g inulin/kg feed, IV) Camaronina + 5 g inulin/kg feed; V) Camaronina + 10 g inulin/kg feed. At the end of the bioassay a PCR was performed to detect WSSV and intestine LAB and yeast were counted. Bioassay 2 (46 days, 0.9 ± 0.05 g): 1) control, Camaronina + DO; 2) Camaronina + Ulva (50 g/kg feed), 3) Camaronina + Ulva (100 g/kg feed), 4) Camaronina + Ulva (150 g/kg feed), and 5) Camaronina + Ulva (200 g/kg feed). Bioassay 3 (73 days, 1.09 ± 0.07 g): I) control (Camaronina); II) 2.5 g inulin + 20% Ulva/kg feed; III) 2.5 g inulin/kg feed (bioassay 1); IV) 20% Ulva/kg feed (bioassay 2). Total hemocyte count and the activity of phenoloxidase (PO) in plasma and prophenoloxidasa (proPO) in the hemocyte lysate supernatant (HLS) were determined. The results were statistically analyzed. Inulin did not increase the number of LAB and yeast in the intestine. Inulin and macroalgae did not affect the growth of shrimp, but the inulin decreased the prevalence of WSSV. The effect of macroalgae against WSSV was not determined. The combination of inulin and U. lactuca significantly increased the number of hemocytes but did not increase phenoloxidase activity in shrimp. Inulin significantly increased the activity of phenoloxidase.