Histological Analysis of the Gill and Swim Bladder of Hong Kong Catfish (Clarias fuscus)

This research aims to characterize the histological features of the gills and swim bladder of adult Hong Kong catfish (Clarias fuscus) weighing an average of 650 g and 40 cm in length. The organs (gills and swim bladders) were dissected and fixed for 48 hours in 10% neutral buffered formalin (NBF) fixative. The organs were then subjected to standard procedures: paraffin embedding, microtome sectioning, staining and mounting, followed by observation under a Carl Zeiss binocular compound microscope. The Gills of Clarias fuscus showed normal primary and secondary gill lamellae. A significant number of lymphocytes infiltrated the gill lamellae. The swim bladder tissues of Clarias fuscus displayed no inflammation, edema or necrosis in the lateral body wall and coelomic cavity. The columnar epithelium has expanded, folded, and filled the swim bladder's lumen entirely. The data acquired can be used to establish a baseline for healthy Hong Kong catfish, aiding researchers in understanding how gill and swim bladder respond to diseases and environmental factors.