The intraspecific variations of otolith and urohyal bone structures in Capoeta fusca (Nikolskii, 1897) (Teleostei: Cyprinidae) in Loot Basin

Hard Structures such as otolith and urohyal have high taxonomical value in intraspecific and interspecific studies of teleostei. In this study the intraspecies variations in morphology and morphometry of the otolith and urohyal bone were investigated in Capoeta fusca (Nikolskii, 1897). Fish specimens were collected from five populations located in Loot Basin in Southern Khorasan province and preserved in 75% ethanol. The otolith and urohyal bones were extracted by standard method, and their morphology described and morphometric characters were analyzed. Results showed the astriscus is the biggest otolith and was gyro-type with major and minor lobus. Astriscus was circle or rectangular between different populations with the inner part concave and the outer part convex. The morphometric analyses showed that populations have significant differences in L.H., RRL and RRH (P<0.05). The anterior part of the urohyal bones was without appendage, and posterior part with deep groove, dorsal plate is more front of ventral edges and its height is equal to ventral edges. End of lateral edges are with dentin structures. The urohyal morphometric analyses indicated that the most relative characters were showed significant differences between all populations. In conclusion, morphologic variations of the asteriscus and urohyal are important in intraspecies and interspecies differentiation.