DAO 36:163-168 (1999)  -  doi:10.3354/dao036163

Effect of dietary β-1,3-glucan on resistance to white spot syndrome virus (WSSV) in postlarval and juvenile Penaeus monodon

Cheng-Fang Chang1,2,*, Mao-Sen Su2, Houng-Yung Chen1, Chu-Fang Lo3, Guang-Hsiung Kou3, I-Chiu Liao4

1Institute of Marine Biology, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC
2Tungkang Marine Laboratory, Taiwan Fisheries Research Institute, Tungkang, Pingtung, Taiwan, ROC
3Department of Zoology, National Taiwan University, Taipei, Taiwan, ROC
4Taiwan Fisheries Research Institute, Keelung, Taiwan, ROC

ABSTRACT: This study evaluated the effectiveness of dietary incorporation of β-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-1 diet) or without β-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. All the surviving shrimp were 2-step WSSV PCR negative 120 d after challenge.

KEY WORDS: β-1,3-glucan · WSSV · Postlarval and juvenile Penaeus monodon

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