## 3 Results
### Reproductive Performance  
All females responded to the hormone treatment, with weight gain exceeding 120% in completely comparable times (Table 2). Comparing pre-migratnt and migrant females show no statistically significant differences (\(p>0.05\)) in weight gain and number of weeks required to reach maximum gonadal development (Table 2).  
No statistically significant differences (\(p>0.05\)) were found in the quantity of eggs emitted (347.9 \(\pm\) 71.9 g pre-migrant; 352.53 \(\pm\) 18.9 g migrant), floating rate and fertilisation rate (Figure 2).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Silver Index** & & **II** & **III** & **IV** & **V** \\ \hline \multirow{3}{*}{Eels (n. 250)} & n. & 14 & 184 & - & 52 \\  & \% & 5.6 & 73.6 & - & 20.8 \\ Body Weight (BW) & g & 431.16 \(\pm\) 120.31 b & 552.34 \(\pm\) 67.05 a & - & 555.44 \(\pm\) 110.73 a \\ Body Length (BL) & mm & 622.44 \(\pm\) 58.36 b & 674.48 \(\pm\) 56.82 a & - & 671.74 \(\pm\) 45.25 a \\ Pectoral Fin Length(PFL) & mm & 28.79 \(\pm\) 3.4 b & 32.81 \(\pm\) 2.60 a & - & 35.47 \(\pm\) 2.12 a \\ Fulton’s Condition Factor & & 1.73 \(\pm\) 0.21 b & 1.81 \(\pm\) 0.17 a & - & 1.83 \(\pm\) 0.28 a \\ Eye Index (EI) & & 3.82 \(\pm\) 0.81 c & 6.26 \(\pm\) 1.02 b & - & 9.28 \(\pm\) 1.86 a \\ Pectoral Fin Length Index(PFI) & & 4.64 \(\pm\) 0.24 c & 4.87 \(\pm\) 0.33 b & - & 5.29 \(\pm\) 0.39 a \\ Gonadosomac Index (GSI) & & 0.64 \(\pm\) 0.31 c & 1.65 \(\pm\) 0.21 b & - & 1.98 \(\pm\) 0.14 a \\ \hline \multirow{3}{*}{Age} & \(<\)6 & - & - & - & - \\  & 6–6+ & 5.3\% & 20 & 5.7 & - \\ \cline{1-1}  & 7–7+ & 62.1\% & 80 & 64.1 & 50 \\ \cline{1-1}  & 8–8+ & 20.8\% & - & 18.9 & - & 33.3 \\ \cline{1-1}  & 9–9+ & 10.4\% & - & 9.4 & 16.7 \\ \cline{1-1}  & 10–10+ & 1.4\% & - & 1.9 & - \\ \cline{1-1}  & \(>\)10+ & - & - & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 2: Zootechnical performance from artificial reproduction trials. Week (n°): means the week of hormonal treatment; Ovulation n°/total: the number of eels that reached ovulation in relation to the total number testedare given as the mean \(\pm\) SD.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Initial**} & \multicolumn{2}{c}{**Final**} & \multicolumn{2}{c}{**Weight Gain**} & \multicolumn{2}{c}{**Ovalation**} & \multicolumn{1}{c}{**Week**} \\  & **Weight (g)** & **Weight (g)** & **(\%)** & **n°/Total** & **(n°)** \\ \hline PRE-MIGRANT III & 618.62 \(\pm\) 62.05 & 762.72 \(\pm\) 79.65 & 123.39 \(\pm\) 6.92 & 10/10 & 20.2 \(\pm\) 2 \\ MIGANT V & 559.94 \(\pm\) 112.4 & 704.72 \(\pm\) 95.05 & 126.51 \(\pm\) 7.65 & 8/10 & 20.4 \(\pm\) 4 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Zootechnical performance from artificial reproduction trials. Week (n°): means the week of hormonal treatment; Ovulation n°/total: the number of eels that reached ovulation in relation to the total number testedare given as the mean \(\pm\) SD.  
No statistically significant differences were found in the hatching rate between pre-migrating and migrating eels, with values of 65.8 \(\pm\) 3.2% and 68.2 \(\pm\) 4.1%, respectively.  
The results of survival rates at 5 days then still in the endogenous feeding stage were similar in the two groups with rates of 46.8 \(\pm\) 4.1% for eel larvae born from pre-migrants and 48.1 \(\pm\) 5.6% for larvae born from migrant eels. At 12 days, the survival rate decreased by almost half in both groups but remained similar with no statistically significant differences in the two groups (25.7 \(\pm\) 5.4% pre-migrants; 27.2 \(\pm\) 3.7% migrants).