Uptake of Mineral Particles by Biomphalaria glabrata (Say.) (Pulmonata,Mollusca) and its Importance for Growth Rate and Egg Production

The ingestion of mineral particles by Biomphalaria glabrata is proved and the importance of these particles in the diet of the snails is investigated. The number of particles ingested rises with the size of the snails and they are retained in quantity in the alimentary tract when an adequate supply is not provided. The size of grit found in the gut differs widely from the mixture offered. Mineral particles are ingested actively and selectively. Quantitative investigations comparing snails cultured with and without sand showed a slight advantage concerning growth and reproduction for snails cultured with sand.