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.

Identification key by scales differentiation for some labrid fishes, Red Sea, Egypt

“…The traditional identification of scale structures revealed the presence of focus, circuli, lateral line canals, radii, lateral fields, posterior fields, anterior field, and shapes of scales (Matondo et al, 2010 andMahmoud et al, 2017). In the present study, shape, margin, focus position and shape, radii, separation line and granulation area of scales in different regions of the fish body may constitute as criteria for differentiating between labrid fish species studied.…”

“…Scale surface morphology provides new and useful information on fish taxonomy. Several characters of scales such as type of scales, size, shape and position of focus is established and being used as a taxonomic tool (Matondo et al, 2010 andAnsari et al, 2016).…”

Describing Scale Shapes of the Male and Female Glossogobius aureus Akihito and Meguro, 1975 from Tumaga River, Zamboanga City, Philippines

“…The general morphology of the scale was evaluated using parameters as described by Matondo et al (2010) and Jawad (2005).…”

“…This may be due to the constant movement of the caudal fin compared to the head region (Table 1). Radii are deep narrow grooves that run in a radial manner towards the focus (Matondo et al, 2010). Primary (1°), secondary (2°) and tertiary (3°) radii were observed in the scale architecture of both sexes of fish.…”

Morphological differences of scales and gill rakers used as a taxonomic character in some thick-lip fish species (Family: Labridae), Red Sea, Egypt.

“…However, some character states of the inter-radial denticles, cteni, and the focus area appear to be good taxonomic criteria (Jawad, 2005). Scales have numerous hidden details in their sculptural design that contributes effectively to fish identification and classification (Matondo et al, 2010).…”