Optimal environment for rearing Hoplobatrachus occipitalis tadpoles and evolution of their mouth cage

Tadpoles or frog larvae are the first stage of evolution. Control of their growth environment is therefore important for rearing. In this context, tadpole rearing trials for the frog Hoplobatrachus occipitalis were carried out in two environments, in concrete basins and in ponds, and the development of their mouth cage was monitored. To this end, 12 mosquito net enclosures were built in ponds and 12 concrete basins on land. To feed these two systems, seven waves of tadpoles were harvested progressively at different locations on the APDRACI fish farm at the start of the rainy season. The main results show that, in terms of physico-chemical parameters, the pH and temperature of the water were slightly higher in the concrete basins. Survival rates and morphological parameters are much higher on average in concrete ponds than in pond enclosures. As for the mouth cage, it begins with two rows of relatively harmless denticles and ends with sharp, pointed teeth. Ultimately, these trials will enable future raniculturists to be more efficient and, above all, to limit tadpole mortality rates.