8 Population Genetics

Abstract

This chapter covers a very broad area of study. A more exact description of the topic presented is the use of isozymic gene frequency data in the understanding of the genetic structure of fish populations. In a recent review, the article Utter et al . discusses what they regard as the most promising direction to be pursued through applications of electrophoretic data in the study of fishes. The present chapter is intended to complement and extend the review of Utter et al . The emphasis is directed toward the use of isozymic genetic data in studies of fish populations with special focus on the application of this data to the culture and management of fish populations. The discussion has been focused on the salmonid fishes because of the importance of salmonids and because of extensive experience with the group, although the same principles are applicable to other organisms. A preliminary methodology section is presented, which emphasizes the amount of genetic information available and the importance of confirming the genetic basis of electrophoretic variants. An overview of some of the areas where isozyme studies have been used in the study of fish populations is followed by a more detailed examination of the concept of the amount and distribution of genetic variation in populations of fish. The final section discusses the management applications of the population genetic data in both artificial and natural populations of fish.