Routine haematological methods for use with fish blood

Some routine haematological methods for examining fish blood are described including haemoglobin estimation, haematocrit, erythrocyte counts, erythrocyte sedimentation rate, total and differential leukocyte counts, and cytochemical staining. Descriptions of stained blood cells are given as are the ranges and mean values for the above tests on brown trout Salmo trutta (L.). These methods are suggested as a possible means of assessing fish health but there is a need for establishing values in health, disease and various stress conditions before their value in diagnosis can be evaluated.