Discrimination between hatchery stocks of silver perch, Bidyanus bidyanus (Mitchell), using scale growth patterns

Abstract

Abstract. A study to develop techniques for assigning cultured silver perch, Bidyanus bidyanus (Mitchell), to their hatchery of origin was conducted using scale growth patterns. Automated video digitizing equipment was used to acquire circuli spacing information. Discriminant function analyses were then used to classify pond-raised fish to their hatchery of origin with up to 91% accuracy. One batch of fish was raised under controlled conditions indoors in a tank to manipulate formation of scale growth patterns. When compared with pond-raised fish, separation was up to 99% accurate. This technique offers scope [or efficient batch marking of pre-stocked fish, thereby improving the ability of managers to evaluate stocking programmes.