Describing variations in scales between sexes of the yellowstriped goatfish, Upeneus vittatus (Forskål, 1775) (Perciformes: Mullidae)

Abstract

Scales have numerous hidden details in their sculptural design that contributes effectively to fish identification and classification. A traditional approach has been made to study the scale morphology of the yellow striped goatfish Upeneus vittatus (Forskål, 1775) using a micron cam attached to a Gateway computer and a stereomicroscope in tandem with a 14 megapixel Kodak easyshare Z 1485 IS digital camera in which digitized images were processed using Corel Paint Photoshop 2x program. To eliminate subjective human error, scale variation in scale images were subjected to Elliptic Fourier Analysis using 77 Fourier descriptors and Principal Component Analysis to discriminate variation between scale shapes within the male and female U. vittatus and to use the data generated to established variation between male and female species. Scanned images (1200dpi) were binarized to generate chain codes using SHAPE 1.3 version. The data were analyzed using Principal Component Analysis conducted using the PAST software ver. 1.8. Result of the study revealed that there is a high significance in the variation of shapes within male and female individuals of U. vittatus and that a significant variation in scale shapes was observed between male and female species. This study demonstrated that scale characteristics can provide useful taxonomic information on the morphological differences between sexes of U. vittatus and that elliptic Fourier analysis and principal Component analysis are good tools to discriminate variation in scale shapes.