Intrapopulation variation of otolith associated with ontogeny and morphological dimorphism in Hormuz tooth‐carp Aphanius hormuzensis (Teleostei: Aphaniidae)

The intrapopulation variation in otolith morphology was investigated for the first time in a recently discovered tooth‐carp Aphanius hormuzensis by considering ontogenetic variation and morphological dimorphism. The otolith materials were examined by scanning electron microscopy and quantitative analyses. The results underlined clear ontogenetic variation in the otolith morphology, which could be valuable to delineate the certain developmental stages of A. hormuzensis. Besides, some otolith features were found to be consistent during fish development and, therefore, appreciated to identify the species. The otoliths of A. hormuzensis demonstrated considerable sexual dimorphism in the adult fishes. Also, morphological side dimorphism was observed more in the otoliths of the females. As a result, the present study designated a clear intrapopulation variation in the otolith of A. hormuzensis, which were mainly influenced by fish development, sexual factors and morphological side dimorphism. The outcomes of the present study provide new basic data on the natural intrapopulation variation of this tooth‐carp during its life history and offered new data to interpret those factors that regulate otolith shape during the development, which has less been considered in previous studies.