%0 Journal Article
%T Effects of Water Temperature on the White Spot Syndrome Virus Infection in Postlarvae Litopenaeus vannamei
%A Sutee WONGMANEEPRATEEP
%A Puttharat BAOPRASERTKUL
%A Piyanuch PROMPAMORN
%A Kanittada THONGKAO
%J Walailak Journal of Science and Technology
%D 2010
%I Walailak University
%R 10.2004/vol7iss2pp127-134
%X This study evaluated the effects of high water temperature (32 ¡À 1 ¡ãC) on the white spot syndrome virus (WSSV) infection in Litopenaeus vannamei postlarvae (PL15). WSSV challenge was done by immersion. One group of PL15 was continuously maintained at 32 ¡À 1 ¡ãC until the end of the experiment after challenge and a control group of PL15 was constantly maintained at 28 ¡À 1 ¡ãC until the end of the experiment after challenge. Other groups were kept at 32 ¡À 1 ¡ãC until temperature was altered from 32 ¡À 1 ¡ãC to 28 ¡À 1 ¡ãC at 0, 1, 3, 5 and 7 days after infection. Gross signs and mortality were monitored every 12 h until the end of the experiment. WSSV infections were confirmed by nested-PCR, histopathology, immunohistochemistry and bioassay methods. Challenged shrimp were kept at 32 ¡À 1 ¡ãC for 0, 1, 3 and 5 days before the temperature was reduced to 28 ¡À 1 ¡ãC revealing that maintaining the temperature at 32 ¡À 1 ¡ãC for a longer period could delay clinical signs and onset of mortalities. Nevertheless, 100 % mortalities occurred in all groups and the control group within 7 days. All moribund PL15 were WSSV-positive by nested-PCR assay as well as histopathology, immunohistochemistry and bioassay methods. In contrast, PL15 constantly maintained at 32 ¡À 1 ¡ãC until the end of the experiment, and for 7 days after challenge before switching to 28 ¡À 1 ¡ãC did not show clinical signs and mortality. Surviving PL15 from both groups were WSSV-negative by nested-PCR assay as well as histopathology, immunohistochemistry and bioassay methods. This study clearly indicated that postlarvae maintained constantly at 32 ¡À 1 ¡ãC for 7 days were able to eliminate/clear WSSV infection.
%K White spot syndrome virus
%K temperature
%K infection
%K Litopenaeus vannamei
%K postlarvae
%U http://wjst.wu.ac.th/index.php/wjst/article/view/36