Effects of environmental factors on diurnal periodicity of tetraspore output in some red algae of Visakhapatnam coast

Effects of environmental factors such as desiccation, salinity, light and temperature on the diurnal periodicity in liberation of tetraspores in Gelidium pusillum, Pterocladia heteroplatos and Gelidiopsis variabilis were studied. Desiccation of fronds, salinity ard continuous dark or light at different intensities had no effect on the diurnal periodicity in spore output in these three red algae. The temperature of sea wat er was the primary factor controlling the peak output of spores. Peak liberation of spores was delayed for 4-12 hr in a day in G. pusillum and G. variabilis when the temperature of sea water was below 30^oC.