Dependence of hatching of Schistosoma haematobium miracidia on physical and biological factors

The effects of light, agitation, and salinity on the hatching pattern of Schistosoma haematobium eggs were examined. Whereas all three factors influenced the hatching pattern, only salinity affected the hatching rate. Eggs began to hatch 5 min after dilution and reached a peak 10-15 min after dilution when urination, dilution of urine, and observation of hatching were conducted under ordinary laboratory conditions (25‡ C in diffuse sunlight). Complete darkness delayed hatching. Agitation of urine by aspiration into a syringe accelerated egg hatching, the miracidia reaching peak numbers 5 min earlier. © 1987 Springer-Verlag.