The access to safe water remains a serious major concern in Africa particularly in rural areas. The aim of this study was to assess the efficiency of pond water treatment consumed by plateau de Batéké population in Bita village using Moringa oleifera seed powder and Vetivera zizanoides root powder. Pond water samples were treated with different concentrations of M. oleifera seeds and V. zizanoides roots as a bio-coagulant. The measurement of physico-chemical parameters in the course of time has permitted to determine the optimum conditions and to evaluate the treatment efficacy. Results revealed that Moringa oleifera seeds are more efficient than Vetivera zizanoides roots. This activity is dose dependent. After one day post-treatment, the rate of turbidity reduction is 93.53% at the concentration of 1.818 g/l. Also, the treatments allowed the reduction of nitrates and nitrites in treated pond water. These results indicate that M. oleifera improve considerably physic-chemical quality of treated pond water. Thus, this approach is ecological and respectful of the environment. It is inexpensive, simple and beneficial for the populations of the rural zones. Moreover, M. oleifera is a plant species particularly easy to cultivate in an intensive way and is adapted to the tropical climate of Africa.

Food and feeding habits of Hippopotamyrus psittacus (Boulenger, 1897; Pisces: Mormyridae) of Congo river has been undertaken from February to July 2007 by the stomach contents analysis. 44 H. psittacus ranging from 55 to 320 mm of length were captured in the Congo River (Wagenia Falls and Kikongo beach). The total length, the standard length and height of the body were measured with a ribbon meter and weighed using both bood scales of 0- 3000gr. Afterward, stomach contents were taken and conserved in the Laboratory for future analysis. Stomachs contents were examined using a binocular magnifying glass LEICA WILDHEERBRUGG Mg model with a magnification of 10 to x50. The stomachs contents analysis showed that H. psittacus is a carnivorous with an insectivorous tendency by feeding mainly on aquatic insects and other animals remnants. On the other side, the food regime of H. psittacus appeared more diversified during the relatively dry season periods. On the same way, the average stomach contents weight indicates that the feeding activity is more or less different during different season periods with an increasing feeding activity during the relatively dry season periods.

This work aims to characterize the structure and diversity of the heterogeneous population of Yoko Forest Reserve. First, we considered (i) the floristic variability (specific richness and diversity), and (ii) the structural variability (in terms of density, ground surface and diametric structure) evaluated at the scale of a hectare. The second step consisted on the analysis of the spatial structure (i) generally and its comparison to the whole plot, and (ii) specific structure of the whole plot (only the spatial structure of the important species was analyzed). So, a systematic inventory of all trees of 10 cm dbh was conducted over five hectares. It should be also noted that the position of each foot has been taken according to the coordinate system (x, y). In total, 1,919 trees of 10 cm dbh were inventoried in five hectares. These individuals were distributed into 98 genera, 141 species and 31 families; with average density of 19.6 genera per hectare, 28.2 species per hectare, and 6.2 families per hectare. The resemblance or similarity degree among the plots (Hectares) showed clearly two coherent plant communities, with a low coefficient of similarity, and each consisting of more or less close plots. Although the density is dominated by Microdesmis yafungana species J. Léonard J. but Pericopsis elata Harms species and Fabaceae family dominated other quantitative parameters. As for the structural analysis, the individuals presented a shape with a significant decrease as we moved to the next class and the most significant densities were observed in classes of diameter 1, 2, 3 and 4. Therefore, a study on the structure and diversity of heterogeneous forest populations is very important because it gives information about the natural processes of trees (growth, regeneration, demographics) as well the anthropogenic action on the forest ecosystem.