Population structure of the ornate goby, Istigobius ornatus (Teleostei: Gobiidae), in the Persian Gulf and Oman Sea as determined by otolith shape variation using ShapeR

Otolith shape variation in the Ornate goby, Istigobius ornatus (Teleostei: Gobiidae), collected along the intertidal coasts of the Persian Gulf and Oman Sea, was analysed using Wavelet transform technique in the ShapeR package to determine population differentiation and structure. There were significant differences (P   0.01). Mantel test showed a positive correlation between the Euclidean distance of otolith shape and geographical distances among populations (r = 0.93, P < 0.002). This indicates that levels in otolith shape resemblance between populations are dependent on geographic distance. Different scenarios are discussed to explain the pattern of otolith shape variation and population structure. Among possible key mechanisms responsible for population differentiations are isolation by distance, Late Pleistocene sea level fluctuations, and ecological and geographical differences between the studied locations. This study highlights otolith shape efficiency as an exceptionally convenient morphological marker to study intraspecific-level evolutionary and contemporary phenomena in marine fish.