Studies on the growth and reproduction of Gracilaria corticata near Mandapam in the Gulf of Mannar

Studies on the growth and reproductive behaviour of Gracilaria corticata carried out at Mandapam and Pudumadam in the Gulf of Mannar, over a period of three years from 1968 to 1970 have been presented, along with some observations on the distribution and harvest of the crop. The growth of the species appears to be irregular and the peak growth occurs during June to August/September and December to February/March, Seasonal changes have not been observed in the abundance of reproductive plants which occurred throughout the year. Tetrasporic plants have predominant in the populations examined at Mandapam and Pudumadam than the sexual plants. Harvesting experiment conducted at Pudumadam showed that the time of harvest and periodic collection of plants influence the rate of production and density of the alga in the natural habitats and that it is profitable to harvest G. corticata twice in a year, during June to August/September and December to February/March.