Phenotype Diversity of Iranian Cichlids Iranocichla spp. in Hormuzgan Basin using the Geometric Morphometrics Technique

In the present study, interspecific morphological diversity and sexual dimorphism of Iranocichla spp. and their distinctness were investigated using the geometric morphometrics method in the water bodies of the Hormozgan Province, Iran. In this regard, 286 specimens of Iranian cichlids were collected from the Mehran, Rasoul, Shoor, and Khoor-e-Goor hot stream and transported to the laboratory. The geometric shapes of the fish were digitized using 17 landmark points and the data were analyzed after removing non-shape data. According to the results, the fishes of Mehran River showed deeper caudal peduncle, higher caudal-fine base, and longer body expressing their adaptation to lentic conditions. Fishes living in pool environments in Khoor-e-Goor have a shorter snout and deeper body showing adaptive phenotypic plasticity to lotic conditions. On the other hand, the fishes of Rasoul and Shoor rivers revealed common traits with other groups showing some morphological adaptations to lotic conditions during rainfall seasons and lentic conditions in dray seasons with rigid selective pressures. Sexual dimorphism of Khoor-e-Goor and Rasoul taxa in head traits may be related to mouth-breeding function in females that need a bigger buccal cavity. Finally, the observed differences between the studied groups can be related to ongoing adaptive phenotypic plasticity to the selective environmental pressures.