Misba Rehman

and 3 more

Scanning electron microscopy (SEM) has significantly advanced morphological studies, particularly in the investigation of fish scale structures. This technique has unveiled intricate architectural details that are crucial for fish identification and classification. In this study, macro- and microscopic analyses were employed to examine the scale morphology of Schizothorax plagiostomus, a vulnerable cyprinid fish from Kashmir, focusing on two body regions (key scales, which were taken from the region below dorsal fin and above lateral line; lateral line scales which were taken from the lateral line). The general scale type observed in Schizothorax plagiostomus was cycloid. Two types of shapes viz., polygonal and cordate were reported in this species. The rostral margin of the scales displayed round and waved forms. The scales exhibited a small and round focus which was antero-centrally positioned. The scales featured narrow or wide grooves (radii) categorized into three types: primary, secondary, and tertiary, present across all four scale fields (anterior, posterior, nuand lateral), forming a tetra-sectioned type. Circuli, arranged in circular patterns around focus were present which were densely placed in anterior and lateral field and widely spaced in posterior field. Notably, lepidonts on the circuli and chromatophores on the posterior margin were absent in this species. These scale characteristics and their morphologies offer a valuable tool for the identification, classification, and phylogenetic analysis of various freshwater fish species and genera.