Unit 1 - Fish Blood Constituents

This unit is concerned with the constituents of fish blood. It also shows examples of the different techniques used in taking and examining blood samples. The regular monitoring of fish blood is a very useful diagnostic tool in establishing the health status of fish farm stocks.

Every effort has been made to ensure that comparable data from representative species are consistently presented.  Therefore, for the purposes of the module, reference will be made throughout to the same species of fishes when indicating figures and proportions of blood cell volumes and constituents.  These species are:

Sea Bass (Dicentrarchus labrax)

White Bream (Diplodus sargus)

Saupe (Sarpa salpa)

Rainbow Trout (Oncorhynchus mykiss)

Nevertheless, it has not proved possible to adhere strictly to these examples because of the difficulty of obtaining blood profiles for single species of fish. It should also be noted that different authors have reported varying figures for the same species.  In many cases, this variation accurately reflects the innate variation in blood parameters between fish of different size, age, and health status and also fish at different stages of sexual maturity. Where data for one of the above-named species are not available, different, though still relevant, examples have been given.