Biomphalaria glabrata: respiration, calcium and end products of carbohydrate metabolism.

1. Lactic acid and succinic acid (end products of anaerobiosis) also occur under aerobic conditions in the haemolymph and excretion products of Biomphalaria glabrata. This phenomenon has been investigated in more detail. 2. Experiments on oxygen uptake, and analyses of organic acid, amino acid and calcium were carried out under various aerating conditions, various temperatures and in various water qualities. 3. No differences were found in the concentrations of the organic acids and calcium in the haemolymph under different aerating conditions. 4. Neither snail-conditioned water, nor artificial crowding effects played a role in the initiation of anaerobic respiration. 5. A low exposure temperature (4 degrees C) initiated anaerobic respiration in spite of the aeration.