A NOTE ON THE EFFECTS OF DRASTIC CHANGES IN TOTAL DISSOLVED SOLIDS ON THE AQUATIC PULMONATE SNAIL BULINUS (PHYSOPSIS) AFRICANUS KRAUSS

Abstract

THE transfer of a sample of Bulinus (Physopsis) africanus from water in their natural habitat containing 490 ppm TDS to a laboratory culture medium of 126 ppm TDS was found to be accompanied by a marked increase in the variability of the rate of oxygen consumption among individuals, and resulted in a 46% mortality. Transfer through the same gradient, but through two acclimatory stages of intermediate dissolved solid content, eliminated both these effects, suggesting an ability to acclimate and therefore to cope with the more gradual changes which may be expected to occur under field conditions.