Results on seasonal growth, fruiting behaviour and spore output inPterocladia heteroplatos are presented. Populations ofP. heteroplatos were recorded in all months of the year with a maximum development of plants from November to January. Tetrasporophytes occurred throughout the year without any seasonal variation in their abundance but carposporophytes were rarely found in natural population. The tetraspore and carpospore outputs ranged from 1427–7 94 055 and 39 996–1 67 040 spores/g fresh weight of the plant respectively. Seasonal changes were not found in the formation and liberation of reproductive bodies inP. heteroplatos.