Snail farming in mature rubber plantation: 4. studies on some artificial methods for hatching of snail eggs and protection of young snails during the dry season

摘要

Three species of edible land snails of the moist forest belt of Nigeria, Archachatina marginata (Swainson), Archachatina papyracae (Pfeiffer) and two phenotypes of Limicolaria species, sometimes named Limicolaria flammae (Muller) and Limicolaria aurora (Jay), were used in the study of three methods of artificial hatching of snail eggs and their young ones for the study of two methods of reduction of mortafity during the dry season. The results of egg laying performance by the three species of snails showed a significantly (p< 0.01) higher population explosion in a given breeding season for L. flammae/aurora than for either A. papyracae or A. marginata. The results of artificial methods for hatching of snail eggs indicated that the use of plastic containers, plus either loose topsoil or cotton wool for the incubator mediums or the use of cellophane containers (bag) plus loose topsoil for the incubator medium, were in each case suitable for adoption in successful hatching of snail eggs artificially. Leaking coagulation pans or wooden boxes, half filled with heat sterilized loose topsoil and placed on the ground under shade of rubber tree canopy as dry season protection methods for the snails, were again in each case effective in the reduction of field mortality of the young snails. The survival rates were 100 percent; 90.6 percent and 71.2 percent for youngs of A. marginata, A. papyracae and L. fiammae/aurora respectively. The results further indicated that the dry season protection method deemedoptimum for the youngs of A. marginata may not necessarily be optimum for the youngs of either A. papyracae or L. flammae/aurora.