Chapter 9 - Analyses of Calcified Structures: Texture and Spacing Patterns

Abstract

Analysis of texture and spacing patterns found in hard body parts is a well-established technique of stock separation. Newer imaging methods have greatly enhanced the approach and increased its power for stock discrimination. The interpretation of texture patterns is partly dependent on the correlation between the growth of the animal and the calcified structure to be analyzed. For example, fish scale growth and the rate of circuli deposition are related. The variation of these features throughout the species' range, as a product of both genetic and environmental influences, allows discrimination of groups with different growth patterns. Therefore, texture patterns of calcified structures relate to phenotypic stocks, which need to be defined to model population dynamics. Spacing patterns can be measured with conventional measurement techniques or with enhanced technologies such as image processing. Simple features, such as the distance from one life history transition zone to another, can be recognized visually and measured manually.