The effect of lordosis severity on juvenile sea bass (Dicentrarchus labrax L., 1758) swimming performance

Authors: FATİH BAŞARAN, HÜSEYİN ÖZBİLGİN, YELİZ DOĞANYILMAZ ÖZBİLGİN, ŞÜKRÜ ŞENOL PARUĞ, OSMAN ÖZDEN

Abstract: The relationship between the lordosis severity and swimming performance in sea bass juveniles was investigated. In total, 149 experimental animals 110-130 days old that ranged from 1.44 to 3.44 g (mean_{TW} ± SD: 2.41 ± 0.49 g) and 5.4 to 6.5 cm (mean_{TL} ± SD: 6.03 ± 0.39 cm) were used in experiments to determine critical swimming speed (U_{crit}) in water that was 14 ± 1 °C. Vertebral angle in normal healthy fish is 180°. The lordosis severity in abnormal fish is indicated by a reduction in this value. Vertebral angles (\varphiº) of the experimental animals in this study ranged from 115° to 180° on the hemal region, and U_{crit} ranged from 32.67 to 44.73 cm s^{-1}. A significant reduction in U_{crit} was observed as lordosis severity increased (decreasing vertebral angle), showing that swimming performance was influenced by vertebral angle deformity in this species. This information has the potential to improve separation methods at commercial hatcheries.

Keywords: Lordosis severity, swimming performance, U_{crit}, sea bass

Full Text: PDF