THE EFFECT OF CERTAIN ENVIRONMENTAL FACTORS ON THE DEVELOPMENT AND HATCHING OF THE EGGS OF BLOOD FLUKES

Abstract

Results from study of development and hatching of the eggs of Spirorchis differ considerably from those secured by Mattes with eggs of Fasciola hepatica. Eggs of Spirorchis contain fully developed miracidia about a week after they are passed in the feces. Ordinary tap water is the most suitable medium for development and hatching of the eggs. The most favorable pH zone for hatching is 7.2-7.6. The miracidia are positively phototrophic. The optimum temp. for development and hatching is 20-25[degree] C. It is postulated that conditions within the egg shell, rather than those in the surrounding medium, cause the opening of the operculum and emergence of the miracidium.