Influence of aqueous extract of macroalga Hypnea musciformis Lamour and Codium tomentosum (Huds) stackhouse at different growth phases of microalgae Chlorella marina (Chlorophyta)

摘要

The microalgae Chlorella marina is used as live feed for feeding larvae and postlarvae of fish and shell-fish in hatcheries or aquaculture. Considering the different bioactivities of the extracts of Hypnea musciformis and Codium tomentosum, experiments were conducted to evaluate their influence on growth promotion in C. marina. The growth response of microalgae Chlorella marina was evaluated using Walne's medium supplemented with different dilutions of the aqueous extract of H. musciformis and C. tomentosum. Results indicated that 0.1 % w/v of the extract of both macroalgae reduced the growth of C. marina to an extent of 25% to 45% initially at its lag phase. A marked increase in growth was observed with the increasing concentrations of the extract compared to the control sets. At its exponential phase, C. marina registered 57.5% increase and 5% decrease in growth in 1 % w/v of the extract of H. musciformis and C. tomentosum respectively.