Abstract: The species and density of benthic diatoms are important factors affecting larval settlement,and juvenile survival and growth in sea cucumber Apostichopus japonicus,which trammels the seed production of the sea cucumber.Thus,the effects of three benthic diatoms Coscinodiscus sp.,Navicula sp.,Amphipteura sp.and combinations and different biomass on larval settlement,and juvenile survival and growth in the sea cucumber were studied.Significantly more larvae were found to settle on Coscinodiscus sp.（13.3%±2.2%） plates compared to Navicula sp.（6.9%±1.8%）,and Amphipteura sp.（5.9%±0.7%） plates in the single benthic diatom species groups（P〈0.05）.In the different benthic diatom combinations,however,there were more larval settlement than those in the unialgal groups（P〈0.05）.A significantly higher number of larvae settled on different benthic diatoms compounding（27.2%±4.28%,density between 1×104 and 25×104 cells/cm2）compared to the control group（18.0%±2.16%）（P〈0.05）.The juveniles in the control group had the maximal growth and survival rate during the 46 day culture,indicating that benthic diatoms are the crucial factors for newly metamorphosed and settled juveniles within 10 days of breeding,and then the juveniles should be fed formulated nutritive diets in time.Mechanism of effects of different benthic diatoms and biomass on larval settlement and growth was discussed in detail.
2010, Vol. 25 
