15 OCTOBER 1999
EFFECT OF DIETARY BETA-1,3-GLUCAN ON RESISTANCE TO WHITE SPOT SYNDROME VIRUS (WSSV) IN POSTLARVAL AND JUVENILE PENAEUS MONODON
C.F. Chang, M.S. Su, H.Y. Chen, C.F. Lo, G.H. Kou, I.C. Liao-1999
Diseases of Aquatic Organisms, 36(3): 163-168 (from Current Contents)
Abstract:
This study evaluated the effectiveness of dietary incorporation of beta-1,3-glucan from Schizophyllum commune in enhancing the resistance of postlarval (PL15) or juvenile (5.5 +/- 0.5 g) Penaeus monodon to white spot syndrome virus (WSSV). The shrimp were fed experimental diets with (2 g/kg diet) or without beta-1,3-glucan for 15 d (postlarvae) or 10 or 20 d (juveniles). Following these dietary treatments, the postlarvae were challenged by immersion and the juveniles by injection using WSSV solution. After challenge with WSSV, initial mortality was significantly (p < 0.005) lower in all the glucan-fed groups than in the respective non-glucan control groups. In the juvenile groups, glucan supplementation for 20 d rather than 10 d significantly (p < 0.005) enhanced survival. After the WSSV challenge. none of the control diet postlarvae or juveniles survived beyond 4 d and none of the 10 d glucan-fed juveniles survived beyond 6 d. By contrast, some of the glucan-treated postlarvae (12.2 %) and some of the 20 d glucan-treated juveniles (20%) were still alive at Day 6. These surviving individuals were reared onwards up to 120 d post-challenge, at which time overall survivals were 5.5 % (postlarvae) and 13.3% (juveniles) and body weights were 25 to 30 g (postlarvae) and 30 to 40 g (juveniles). Half of the surviving postlarvae and 58% of the surviving juveniles were 2-step WSSV polymerase chain reaction (PCR) negative 6 d after challenge. FLU the surviving shrimp were 2-step WSSV PCR negative 120 d after challenge.
(Natl Sun Yat Sen Univ, Inst Marine Biol, Kaohsiung 80424, Taiwan, e-mail: changch@ms3.hinet.net)