Histological Changes in the Hepatopancreas and Stomach of Litopenaeus vannamei Experimentally Induced with White Spot Syndrome Virus Infection
May Flor S. Muegue *
Institute of Fish Processing Technology, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
Philip Ian P. Padilla
Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
Ma. Ramela Angela C. Bermeo-Capunong
Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
Christopher Marlowe A. Caipang
Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
Rommel J. Gestuveo
Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
Mary Jane A. Amar
Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
Jane S. Geduspan
Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines.
*Author to whom correspondence should be addressed.
Abstract
Litopenaeus vannamei is an important aquaculture species in the Philippines and in the world. Its production continues to increase due to its fast growth and lower protein requirement, making it a favorable species to culture. However, sustainability of the this industry is hampered by the occurrence of viral diseases. White spot syndrome virus (WSSV) is considered the most devastating shrimp viral pathogen which can cause up to 100% mortality few days upon the onset of the infection. To understand the rapid mortality of the infected shrimps, this study examined histological changes in the stomach and hepatopancreas of Litopenaeus vannamei induced with WSSV infection. Results showed that cells in the stomach of infected L. vannamei undergo cellular abnormalities including hypertrophied nucleus, chromatin margination and basophilic inclusion bodies. The hepatopancreas was also observed to present basophilic inclusion bodies and chromatin margination. Disruption of the tubular epithelium in the hepatopancreas were further observed. These cellular damages that result to tissue and organ destruction as the infection progresses lead to the loss of the functions of these organs which probably contributed to the rapid mortality of shrimp infected with WSSV.
Keywords: White spot syndrome virus, Litopennaeus vannamei, hypertrophied nucleus, chromatin margination, basophilic inclusion bodies