Accumulation and excretion of aluminium and iron by the terrestrial snail Helix aspersa

Abstract

1. The snail Helix aspersa was fed one 24 hr meal containing Al, Fe or both together in barley flour pellets. Accumulation and distribution within the digestive gland, kidney, crop and remaining soft tissues were examined over the subsequent 30 days using atomic absorption spectroscopy (A.A.S.). 2. The digestive gland contained significantly ( P < 0.05) elevated levels of Al and Fe for 8 and 12 days. The digestive gland is the major sink for both Al and Fe in Helix. 3. The kidney rapidly accumulated Al and Fe but the increase was short-lived. The kidney may therefore be involved in the elimination of metal not incorporated into the digestive gland. 4. Iron was absorbed by the crop but Al was not. This may indicate a route of uptake of Fe into the digestive gland not shared with Al. 5. No obvious pattern of accumulation of Al and Fe were seen in the remaining soft tissues or the blood of Helix. 6. Aluminium is present in the faeces for 12 days suggesting that Al is released relatively slowly. 7. Presence of both Al and Fe in the feed induced a change in the pattern of accumulation in the digestive gland but not in the kidney, crop and remaining soft tissues. 8. The distribution of Al is discussed in relation to the suggestion that Al follows the ferretin pathway during accumulation.