Spatial variation in relationships of otolith measurements with body length of Prussian carp, Carassius gibelio (Bloch, 1782) collected from four lentic habitats in Samsun Province, Türkiye

This study aimed to disclose the spatial variability in the lagenar otolith (asteriscus) dimensions-total length relationships generated for four Prussian carp, Carassius gibelio (Bloch, 1782) populations (Altınkaya Dam Lake, Bafra Fish Lakes, Lake Ladik and Lake Simenit) in Samsun Province, Türkiye. Relationship between length and weight of the fish was also described for each population. Samples were obtained from commercial fishermen in different periods between February 2017 and March 2018. The length, height, and weight of each otolith were determined. A non-linear function was used to define allometric relationships between asteriscus measurements and body size. The slopes of the regressions acquired for the right and left otoliths at each sampling site did not show any significant difference. All of the relationships were found to be statistically significant (P<0.001). The r2 values ranged from 0.61 to 0.95, and the mean values of the percent prediction error varied from 3.10 to 7.45. The ANCOVA test determined significant spatial differences in regression slopes for the three otolith variables. Our findings revealed that otolith development reflected somatic growth, but this varied by sampling area.