Studies on tetraspores shedding in Padina tetrastromatica Hauck

Studies on the tetraspores shedding varied seasonally in this brown alga with peak shedding of spores in the month of February. Diurnal periodicity was observed with peak output of spores between 06:00 and 10:00 hours in all eight months of the year of it's occurrence on the coast without any shift in the peak shedding. Effect of environmental factors were studied on spore shedding and diurnal periodicity. spore shedding decreased with increase in the duration of exposure of fronds to air and max. quantity of spores were obtained under submerged conditions. The spore shedding also varied in the different salinities and the peak liberation of spores was observed at 35%o salinity. The quantity of spores liberated at different light intensities also varied and the maximum shedding was observed at 1000 Lux light intensities. The max. liberation of spores was observed at 24L:0D cycle and the experiments conducted with coloured lights of different wavelength show that the spore output was max. in white light.Environmental parameters such as desiccation,salinity & wavelengths didn't effect the diurnal periodicity,but spore shedding was changed in light intensities and photoperiod.