Stock-Specific Variation in Scale Morphology of Atlantic Striped Bass

摘要

We examined scales of wild striped bassMorone saxatilisto determine whether scale morphology differs systematically among three Atlantic coast stocks and thus could be used for stock discrimination. Morphological variables investigated included Fourier coefficients, ratio shape descriptors (circularity, rectangularity), truss networks, perimeter landmarks, width and spacing of the first 10 circuli, and angular measurements of the scale interior. A variable was considered potentially useful for stock identification if it could be corrected for size variation, did not show year-class effects, and showed significant stock-of-origin effects in a multivariate analysis of variance. Fourier shape descriptors, rectangularity, and angular measurements of the scale interior showed the greatest potential for discrimination of Atlantic striped bass stocks. In addition, circulus patterns showed some usefulness. The remainder of the morphometric variables appeared less useful either because of failure to meet statistical assumptions for size correction (truss networks and perimeter landmarks), significant year-class effects (circulus patterns), or a paucity of significant stock-of-origin effects (truss networks, circulus patterns, circularity). Relatively few strong correlations (r≥ 0.70) were evident among morphological variables of different types.