## 3 Results  
### Experiment 1 in Bukavu, Eastern Highlands DR Congo  
For the two parameters FBW and CF for which individual values were available, there were significant effects of pond and feed on both, but the strain effect was significant only on CF (Table 2). The strain \(\times\) feed interaction was significant for FBW and CF, suggesting varied responses by different strains to different feeds. For the four parameters for which only mean values per hapa were available, the effects of pond and feed were significant only for WG and FCR, and the effect of strain was only significant for WG. The significant interaction between strain and feed for FBW and CF means that it is necessary to interpret the differences among the six strain \(\times\) feed combinations rather than the effect of strain or feed alone. Therefore, only the significant differences among strain \(\times\) feed combinations are indicated in Table 3. They showed that the Lake Kivu fish had significantly higher FBW when fed the commercial and fishmeal-free feeds compared with the Nyakabera strain, but when fed the fishmeal-based feed the difference was not significant. When fed the two non-commercial feeds the Lake Kivu fish had significantly higher CF than Nyakabera fish but not when fed on the commercial feed. For parameters for which mean values for hapas were available (WG, FCR, HSI, GSI, PER and LER), the lack of significant interaction permits meaningful identification of significant main effects of strain and feed (Table 3). Of these parameters, only WG was significantly different between strains, with the Lake Kivu strain growing faster than the Nyakabera. Fish fed the commercial feed had significantly greater WG and better FCR than fish fed the other two feeds, which did not differ significantly from each other (Table 3). FI was significantly greater and LER significantly lower for fish fed the local fishmeal-based feed than fish fed the other two feeds, which did not differ significantly from each other. In contrast, fish fed fishmeal-free feed had significantly higher PER than fish fed the other two feeds, which did not differ significantly from each other. The fish fed the fishmeal-free feed had significantly lower survival than those fed the fishmeal-based feeds. However, the survival of fish fed the commercial feed was not significantly different from that of fish fed the other two feeds. There were no significant differences among the three feeds for HSI and GSI. The strain \(\times\) feed interaction and the strain and the feed main effects were not significant on the fish whole body dry matter, crude protein, ash, total carbohydrate and gross energy (Table 4). The strain effect was significant only for the whole body crude lipid, with the Nyakabera strain showing higher fish whole body crude lipid than the Lake Kivu strain. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**Effect \({}^{\dagger}\)** & **FBW** & **CF** & **WG** & **FCR** & **HSI** & **GSI** & **PER** & **LER** \\ \hline Pond & 83.5 *** & 76.9 *** & 21.6 *** & 4.5 * & 2.5 \({}^{\text{NS}}\) & 1.6 \({}^{\text{NS}}\) & - & - \\ Strain & 3.2 \({}^{\text{NS}}\) & 26.3 *** & 0.7 ** & 0.6 \({}^{\text{NS}}\) & 0.0 \({}^{\text{NS}}\) & 0.02 \({}^{\text{NS}}\) & 0.14 \({}^{\text{NS}}\) & 0.01 \({}^{\text{NS}}\) \\ Feed & 113.8 *** & 36.5 *** & 28.3 *** & 4.5 * & 0.8 \({}^{\text{NS}}\) & 1.34 \({}^{\text{NS}}\) & 8.98 ** & 64.4 *** \\ Strain \(\times\) feed & 12.2 *** & 17.4 *** & 3.0 \({}^{\text{NS}}\) & 1.2 \({}^{\text{NS}}\) & 0.1 \({}^{\text{NS}}\) & 0.33 \({}^{\text{NS}}\) & NS & NS \\ \hline \end{tabular} \({}^{\dagger}\): Significant levels are indicated as *** = \(p\) \(<\) 0.001, ** = \(p\) \(<\) 0.01, * = \(p\) \(<\) 0.05 and \({}^{\text{NS}}\) = Not significant.  
\end{table}