Determination of otolith biometry, asymmetry and morphological characteristics of boops boops (linnaeus, 1758) and pagellus acarne (risso,1827) (sparidae) from fethiye bay

Sparidae is one of the families that includes economically important species distributed in the Marmara Sea and the Mediterranean. This study aimed to investigate the otolith biometry, asymmetry and morphology of Pagellus acarne (Axillary seabream) and Boops boops (Bogue) species from the Sparidae inhabiting Fethiye Bay. Length-weight and length-length relationships, otolith shape variables, otolith mass asymmetries and otolith fluctuating asymmetries of B. boops (n=130) and P. acarne (n=147) individuals sampled from Fethiye Bay were calculated. In addition, Scanning Electron Microscope (SEM) images of sagittal otoliths of both species were also performed. The average weight and total length of B. boops individuals were 41.43±12.274 g and 16.0±1.409 cm, respectively. The average weight of P. acarne individuals was determined as 37.83±10.272 g and the average total length was determined as 13.90±1.073 cm. The total lengthweight relationship for all B. boops individuals was determined as W=0.0024TL3.506 (R2=0.916) and the total length-weight relationship for all P. acarne individuals was determined as W=0.0095TL3.137 (R2=0.944). It was determined that B. boops and P. acarne showed positive allometric growth in Fethiye Gulf. In order to determine otolith morphology, biometry and asymmetry of P. acarne and B. boops, sagittal otoliths were removed in pairs. Weight (OW), length (OL), width (WO), area (A) and perimeter (P) values of otoliths were measured. A statistically significant difference was found between the right and left otoliths of P. acarne and B. boops individuals in terms of both otolith width and otolith length (p<0.05). The average length-width ratio values of the right and left otoliths of P. acarne were calculated as 1.7448 and 1.7523 (p<0.05), respectively, the average ellipticity values were 0.2713 and 0.2733 (p<0.05), respectively, and the average relative otolith length values were 39.7428 and 39.000 (p<0.05), respectively. The average roundness values of the right and left otoliths of B. boops were determined as 0.5192 and 0.5093 (p<0.05), the average rectangularity values were determined as 0.6867 and 0.6764 (p<0.05), and the average relative otolith length values were determined as 35.1266 and 35.8057 (p<0.05), respectively. The otolith mass asymmetry of B. boops individuals was found between -0.0684 and 0.0342, while the otolith mass asymmetry of P. acarne individuals was found between -0.0842 and 0.0842. The highest fluctuating asymmetry value in otolith width, otolith length and otolith area characters in B. boops individuals was observed in the 170-179 mm length group and the highest fluctuating asymmetry value in otolith circumference character was observed in the 120-129 mm length group. In P. acarne individuals, the highest fluctuating asymmetry value for otolith width was observed in the 140-159 mm length group, while the highest fluctuating asymmetry values for otolith length, otolith area and otolith circumference were observed in the 120-139 mm length group. In this study, important first data on otolith morphology, biometry and asymmetry of B. boops and P. acarne inhabiting Fethiye Gulf were presented and an attempt was made to contribute to the understanding of the population structure of these species. The findings obtained show that the growth characteristics of the species and asymmetries in otolith structures may be related to biological and environmental factors.