Neutral lipids in snail-conditioned water fromBiomphalaria glabrata (Gastropoda: Planorbidae)

Thin-layer chromatography was used to study neutral lipids in snail-conditioned water (SCW) fromBiomphalaria glabrata snails. A major lipid fraction in SCW at 2 and 4 hr after snail incubation contained free fatty acids. Fatty acids released per snail per milliliter of water when 10 snails were incubated in 5 ml of deionized water for 4 or 2 hr was 2.4±0.4 µg/ml and 0.9±0.1 µg/ml (mean ± SE), respectively. The amount released at 4 hr was significantly greater than at 2 hr. Snails also released free sterols, a sterol ester-hydrocarbon fraction, methyl esters, and other unidentified lipid fractions into the water. The potential of these neutral lipids to serve as chemoattractants for larval trematodes or snails remains to be determined.