The urohyal bone and asteriscus morphology in Capoeta saadii (Heckel, 1847) collected from the Kerman Basin

In this study, the intraspecific variations in urohyal bone and otolith morphology were investigated in Capoeta saadii (Heckel, 1847) from Kerman Basin. A total of 48 specimens from four populations (Zarand, Bardsir, Kouhbanan, and Kahnooj) were collected from Kerman province and preserved in 75% ethanol. The urohyal bones and otoliths were extracted by the standard methods, and their morphology described and morphometric characters were analyzed. The urohyal bones are characterized by the following features: the anterior part without appendage, the ventral surface triangular in shape and with slit in the posterior part of the urohyal bone, the ventral sides is almost wide. The asteriscus otoliths were gyro-type and often with no clear rostrum and pseudorostrum, the inner part concave and the outer part convex, the ventral rim is straight and serrated. The morphometric analyses indicated that the L/PosD, L/In.O.D, W/PosD and W/In.O.D have the most important role in differentiation of the studied populations. In the case of asteriscus, ML/FSL and ML/FHL are important in differentiation of the studied populations. Based on the results of the current study, it can be concluded that variations in morphology of the urohyal bone and asteriscus in cyprinids can be important not only in the species discrimination but also for estimation of the intraspecific differentiation (variations among populations) in allopatric populations. By considering the pattern of variation of the studied structures, the Zarand population is differentiated from the others, and this can probably be resulted by its geographic isolation.