Effects of chemical cues on larval survival, settlement and metamorphosis of abalone Haliotis asinina

Low larval survival poor settlement, and abnormal metamorphosis are major problems in seed production of donkey-ear abalone Haliotis asinina We examined the effects of chemical cues including epinephrine, nor-epinephrine, and serotonin on larval survival, settlement, and metamorphosis m order to determine the possibility of using these chemicals to induce the problems The results show that epinephrine could enhance metamorphosis rate at 10(6) mol/L only but higher concentrations (10(3)-10(4) mol/L) and nor-epinephrine could inhibit the performance significantly, and serotonin could increase significantly the performance at a wide-range concentration (10(3)-10(6) mol/L) Treatment with serotonin at 10(5) mol/L for 72 hours resulted in the highest settlement rate (42 2%) and survival rate (49 3%), while at 10(-4) mol/L for 72 hours resulted in the highest metamorphosis rate (38 8%) Therefore, serotonin may be used as a fast metamorphosis inducer in abalone culture