Pathological microscopy in liver parenchyma of gray-eel catfish, Plotosus canius, from Ang-Sila area, Chonburi Province, Thailand

Abstract

This is the first discovered abnormal liver of gray-eel catfish (Plotosus canius), which was collected from the Ang-Sila area, Chonburi Province, Thailand. Anatomically, the liver tissue was observed to be both shrunken in overall appearance and with almost white colorization in all lobules. Based on histological and histochemical observations, the liver parenchyma in this species was clearly altered. A large number of vacuolar structures in the hepatocyte were shown as empty spaces (H&E stained), but these structures appeared after the ORO reaction as orange color, indicative of hepatocellular lipidosis. The loss of glycogen in hepatocytes was also observed by using PAS reaction. In addition, necrosis with poor sinusoids structure was occasionally seen in some liver areas. All abnormalities seen in these liver samples might be related to reduced functionality as well as health status of P. canius; further, the altered health of these fish might interfere with other animals/ humans within ecological dynamic., Overall, results shown here demonstrate the importance of anatomical and histological studies and we suggest such studies should be incorporated into water quality monitoring in the Ang-Sila zone of Thailand and represent an important consideration for other locations around the world.