Brown mussel Perna indica contribute 15% of the total mussel production in India. This species spawns from June to August from Quilon to Cape Comorin. The spat settlement in the natural bed was observed from July to September and the peak mode of spat size in the natural bed and the growth rate were estimated. Regular sampling from natural bed was done to observe the density and changes in the spat settlement pattern. The byssogenesis of spat ranging from 5-35 mm were studied in the laboratory condition. The effect of temperature, salinity and dissolved oxygen on spawning and settlement are also presented in this paper.