Hydroacoustic surveys are one of the prime methods to assess the commercially top-ranked small pelagic stocks. The method relies on acoustic scattering from a fish, which is largely controlled by the size and morphology of the swimbladder. In this study, the changes in the size of the European anchovy swimbladder sampled in the Black Sea were investigated. Ventral cross-sectional area (by photographing the ventrally dissected fish) and volume (by dorsal and lateral X-raying) of the swimbladders were estimated. Comparison of areas showed that the stomach fill and presence of viscera did not have a statistically significant impact on the swimbladder size while the hepatosomatic index showed significant impact. |
