## 3 Results
Comparing the sex of fish within the same reproductive stage and sampling area, the value of THg from open sea was significantly higher in females than in males; this \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Reproductive** & **Sex** & **Sampling** & **Length, cm** & **Weight, g** & **Total Hg** & **Total Lipids** \\
**Stage** & **Area** & & **(Min–Max)** & **(Min–Max)** & **mg kg\({}^{-1}\) ww** & **g/100 g** \\ \hline Post-spawning & Female & Open sea & 31 & 16 \(\pm\) 2 & 42 \(\pm\) 17 & 0.12 \(\pm\) 0.01 & 7.87 \(\pm\) 0.07 \\  & Female & Coast & 80 & 15 \(\pm\) 2 & 35 \(\pm\) 13 & 0.05 \(\pm\) 0.01 & 2.59 \(\pm\) 0.14 \\ Post-spawning & Male & Open sea & 58 & 13 \(\pm\) 1 & 23 \(\pm\) 9 & 0.23 \(\pm\) 0.01 & 0.44 \(\pm\) 0.03 \\  & & Coast & 20 & 13 \(\pm\) 1 & 22 \(\pm\) 5 & 0.24 \(\pm\) 0.01 & 1.82 \(\pm\) 0.08 \\  & & Total & 189 & 14 \(\pm\) 2 & 31 \(\pm\) 10 & 0.16 \(\pm\) 0.09 & 3.18 \(\pm\) 3.25 \\  & & & & (13–16) & (22–42) & (0.05–0.24) & (0.44–7.87) \\ \hline Grand total & & 407 & 13 \(\pm\) 2 & 27 \(\pm\) 12 & 0.20 \(\pm\) 0.15 & 3.29 \(\pm\) 2.43 \\  & & & (10–17) & (9–49) & (0.03–0.62) & (0.44–7.87) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._  
Figure 2: Concentrations of THg (mg kg\({}^{-1}\) wet weight) in various reproductive stages of _M. barhatus_ in females (**a**) and males (**b**). Different lower-case letters indicate statistically significant (\(p\) < 0.05) differences between groups sampled from the same site. * Indicates statistically significant difference between males and females of the same life stage (\(p\) < 0.05). finding was observed in all life stages, except in post-spawning, where females showed a lower THg content than males (\(p<0.0001\)). With regards to fish that were sampled from coastal area, females showed a statistically significant higher THg content both in adult and spawning phases, compared to males. Otherwise, juvenile and post-spawning females showed a THg content that was significantly lower than in males (\(p<0.0001\)). The lipid content ranged from 0.44 (post-spawning males in open sea area) to 7.87 (post-spawning females in open sea area) g/100 g wet weight. The value of lipid content was significantly lower in males that were collected in open sea area, compared to other coastal related samples (\(p=0.008\)). Taking into consideration the variations in total lipid content based on the reproductive stage of fish, all investigated samples highlighted a bell-shaped trend. This trend showed that lipid content grew in the spawning phase and decreased during the post-spawning phase, with the exception of post-spawning females caught from open sea (Table 1). The relationship between THg content and lipid content was also investigated; no statistically significant correlation (\(p>0.05\)) between the two parameters was found (Table 1). Although a positive linear trend between these two parameters was identified (r = 0.41, \(p=0.118\)), fish length was not statistically correlated with THg content. A principal component analysis (PCA) was applied to the samples, considering the variables of Hg level, lipid content, sample length, and weight (Figure 3). This was made in order to reduce the dimensionality of the data matrix, and more easily visualize the results to interpret data. The PCA extracted two significant, cross-validated principal components which account for 93.75% of the variability in the original data (Table 2). The first principal component (PC1, 66.68%) is dominated by biometric parameters and lipid content (Table 2). Juvenile specimens showed the lowest values of weight, length, and lipid content (negative scores), both for male and female. Considering the other reproductive stages, females (positive scores) were associated with higher biometrics values and higher lipid content than males (mainly negative scores).