Effects of sexual maturity and feeding on condition of a deep‐sea flatfish, Lepidorhombus boscii, in north‐eastern Mediterranean waters

Abstract

The condition factor (K), the hepatosomatic index (HSI), the muscle total lipid content (TLC), the gonadosomatic index (GSI) and the stomach somatic index (SSI) of the four‐spotted megrim Lepidorhombus boscii in the Aegean Sea were investigated as a function of season, gender and length to study relations of condition with feeding and maturity of specimens. The application of GLM analysis of covariance provided significant models for GSI, K, and TLC over most seasons and revealed the significant effect of gender on GSI, and of length on K and TLC, as well as the existence of significant interactions between the two factors. On the other hand, GLMs for HSI and SSI were either non‐significant or very poor in explaining the variability of the two indices. Pearson's correlation coefficient showed a strong positive association between K and TLC, and both variables were negatively correlated to GSI in both sexes during most seasons. Our findings suggested that decreased condition was shown mainly by small specimens, and also by adult females, particularly during the spawning season, demonstrating, respectively, the increased energetic demands for growth in juveniles and for oogenesis in mature females that might have become more prominent due to the oligotrophic character of the study area.

Keywords:

• condition
• lipids
• maturity
• feeding
• flatfish
• Aegean