Effect of statistically significant independent variables on the dependent variables examined according to the generalized additive models (GAMs) results. Dashed lines indicate 95% confidence intervals. Top row: total length (TL), second row: gonadosomatic index (GSI), third row: hepatosomatic index (HSI), bottom: condition factor (CF). Day number = 0: 31/10/2013 (first sampling day for catch data). Unknown: unidentified sex (immature individuals of stage-1 or individuals at spent gonad stage unidentifiable regarding sex). First day of each season and January 1st indicated by vertical lines.