The Developmental Changes in the Morphology of the Asterisci Otoliths of Cyprinion kais (Heckel, 1843) and Cyprinion macrostomum (Heckel, 1843) Collected From Tigris River, Şırnak Province, Türkiye

A series of asterisci otoliths of C. kais and C. macrostomum freshwater fish species from the Tigris River, Şırnak Province, Türkiye, are designated morphologically to explore the ontogenetic and intraspecific disparity. The outcomes of this study show that the surface morphology of the asterisci among young and adult specimens is inconstant, particularly in C. macrostomum. The indicative characteristics of the asterisci can be utilised to approve the identification of the species. Besides, the collection of fishes from the Tigris River, Şırnak Province permitted the inspection of larger maximum sizes than reported in the literature for both species of the genus Cyprinion explored. The present study represents the first developmental account of the asterisci of any cyprinid fish species examined before. An SEM-based result of the asterisci of the two species is presented.