Seasonal variation in health status of small endangered open water fishes from Kongsa river and Noli beel

SEASONAL VARIATION OF HEALTH STATUS OF SIS IN TWO BEELS

Abstract

Investigation of health status of three small indigenous fishes Lepidocephalichthys guntea, Monopterus cuchia and Colisa fasciata from Kongsa river near Jaria, Netrokona and Noli beel near Kapasia, Gazipur district were carried out through clinical and histopathological observations during September 2014 to May 2015. Fish samplings were done on monthly basis. Clinically, all the experimental fishes were normal and healthy appearance in summer season i.e; March to May from both water bodies. Weak body, faded colour and scale loss had in all three fishes during autumn. However, in winter, rough skin, red spots in ventral region, weak body, loss of caudal fin, discoloration of gill filaments and several necrotic lesions on head region were found in all three fishes from both sampling sites. Histopathologically, organs of all investigated fishes had almost normal structure during summer. In autumn season, epidermis was partly or totally lost, dermis sloughed off, vacumm and hemorrhage were found. However, during winter, epidermis was lost, macrophage centre, fungal granuloma, hemorrhage, necrosis and vacumm were observed in three experimental fishes of both sampling stations. Fishes of Noli beel were found to be more affected then fishes of Kangsa river. Among fish species, Lepidocephalichthys guntea was observed more affected than other fishes and less affected one was Colisa fasciata. Overall, based on clinical and histological point of view, fishes were found to be more affected during winter season. Whereas, in summer pathological condition of fish gradually healed up to normal except few vacuums and hemorrhage. In clinical and histopathological observations, open water fishes were more susceptible due to EUS.