Analysis of Phagocytosis of Fish Leucocytes Using a Bacterial Thin-layer Method

Abstract

A method for estimating phagocytic activity of leucocytes using a bacterial thin-layer was applied for carp and rainbow trout leucocytes against Edwardsiella tarda. Blood was added onto petri dishes of which the buttom was coated with the bacteria. The number and area of plaques formed on the thin-layer were measured as indices of phagocytic activity at 10, 20 and 30°C using a computer program. Phagocytosis of carp leucocytes was most active at 30°C. In rainbow trout, the total plaque area and number of plaques were maximal at 20°C and average plaque area was largest at 30°C.