Stock identification of the Indian halibut, Psettodes erumei (Bloch Schneider, 1801) (Pisces: Psettodidae) using otolith shape in small-scale fisheries

The otolith shape of the Indian halibut, Psettodes erumei, from the Persian Gulf, Hormuz Strait and the Oman Sea were studied to discriminate the fish populations in small-scale fisheries. Indian halibut is a commercially valuable flatfish species abundantly caught in the north of the Persian Gulf and Oman Sea. Identifying different stocks is one of the main issues for fishery management programs. In this study, four otolith measurements (surface area, perimeter, length, and width) and five shape indices (from factor, roundness, circularity, rectangularity, and ellipticity) were recorded. The morphological analyses showed a significant asymmetry between the eyed and blind sides of otoliths. The otolith shape was described by shape indices and then, compared using a canonical discriminant analysis (CDA). The shape indices did not display any significantly different mean values among areas. Also, the patterns derived from CDA did not show any separation among populations. The absence of a disparity in the otolith shape indices could be linked to the similar condition of environment and nutrition in the regions and to the ecological behavior of the species. The results of this study may improve the accuracy of decision-making in the fisheries monitoring and management of P. erumei in the Persian Gulf and Oman Sea.