Fish Diseases and Management

Fresh preparations

It is essential to keep the fish moist preferably with water from which it was removed. Many of the parasites are detected primarily by their movement. If they are allowed to dry out or placed in chlorinated tap water they will die rapidly.

Fresh skin scrapings are obtained by gently scrapping the surface of the fish especially behind fins e.g. dorsal and pectoral with a scalpel blade. The collected scrapings consisting of mucus with epithelial cells is transferred to a glass slide with a drop of the water in which the fish was kept and  cover-slipped. The slide is then examined under the microscope for the presence of  parasites.

A portion of the gill primary lamella is then cut and removed from the gills and placed on a glass slide and cover-slipped with a drop of water. The tissue is then moved and pressed slightly for observing the secondary lamellae. The preparation is then examined under the microscope.