Study of parasitic disease of greenback mullet (Planiliza subviridis) in Samut Sakorn Province

Abstract

Parasitic disease is a serious problem both in aquaculture systems for farmers and consumer. Twelve fish samples of greenback mullet (Planiliza subviridis) were collected from natural canal in sub-district Khokkharm, Muang, Samut Sakorn province. Fish samples were kept in ice box and transported to the laboratory for examination. In the laboratory, fish were measured and examined the ectoparaste by wet smear technique from mucus and gill under the microscope. Fish muscle was digested by digestive juice (pepsin) and examined under the microscope. Parasites were recorded and counted. Some fish tissues (gill, liver, spleen, and kidney) were fixed by 10% neutral buffered formalin, dehydrated, embedded, sectioned, stained by hematoxylin and eosin, mounted by permount, and made to permanent slide for histopathology study. The results showed four parasites were found from Planiliza subviridis (Trichodina sp., Myxobolus sp., Ligophorus sp., and Stellantchasmus sp.). The overall prevalence of parasites was 100, 16.66, 91.66, and 91.66%, respectively. The mean intensity of parasites was 90, 5.5, 19, and 289.25, respectively. Histopathology changes showed hyperplasia and degeneration of gills epithelial cells. Metacercariae of Stellantchasmus sp. were found in spleen and kidney. Melanomacrophage centre (MMC) and hemorrhage were found in spleen, whereas the degeneration of renal tubule was found in kidney. Based on this information indicated the natural greenback mullet harbored both ectoparasite and endoparasites that affect fish health and may affect to consumer, especially the raw meat consumers.