A simple method for culturing neonatal Biomphalaria glabrata snails.

A simplified method for the culture of neonatal Biomphalaria glabrata snails on a diet of the cyanobacteria Nostoc sp. has been developed. Previous studies reported using Nostoc sp. grown on a mud-based medium to feed neonatal snails; this medium is difficult to prepare and gives inconsistent growth between laboratories due to variations in the soil used in its preparation. Here, we report the use of Bg-11 medium supplemented with sodium nitrate for the culture of Nostoc sp. as a food source for neonatal B. glabrata snails. Bacteria grown in the medium may be maintained in continuous culture and used exclusively as the nutrient source for neonatal snails. Neonatal snails fed with these bacteria exhibit a growth rate of 1-2 mm per week and may be transferred to standard culture conditions after 2-3 wk. Survival of neonatal snails after 2 wk on the Nostoc sp. diet was 60-80%, while survival after switching to standard culture conditions approached 100%. Analysis of the growth rate and survival of neonatal snails maintained on Nostoc sp., as well as the growth rate, survival, and sexual maturation of the resulting juvenile snails, showed that snails maintained using this method are phenotypically comparable to those maintained under other standard laboratory conditions.