僧帽牡蛎幼体附着和变态的诱导

采用外加人工化学物质检验对僧帽牡蛎眼点幼体的附着和变态诱导活性,结果表明去甲肾上腺素、野上腺素和L-多巴可有效诱导幼体不固着变态.在药物持续作用下,肾上腺素的最佳诱导浓度为10-5mol@L-1(变态率67.4%),去甲肾上腺素的最佳诱导浓度为5×10-5mol@L-1(变态率52.2%),L-多巴的最佳诱导浓度为10-5mol@L-1(变态率43.0%),而对照组变态率为0.幼体大多在药物作用12～24h之间完成变态.三种药物诱导的变态个体中有85%以上是不固着变态.比较多种附着基和EPI的变态诱导活性,显示同种贝壳的活性较肾上腺素还高.去甲肾上腺素诱导幼体变态效应对低盐海水有较强耐受能力,而对高盐海水适应性差.

Induction of settlement and metamorphosis of Saccostrea cucullata larvae

Induction of adding chemical compounds on the sett lement metamorphosis of Saccostreea cucullata larvae was assayed. The metamorphosis of larval Saccostreea cucullata can be induced by epinephrine ( EPI) , Norepinephrine ( NE) , and L - DOPA. During a 48h exposure, optimum concentrat ions of three compounds were 10- 5mol..L- 1, 5 .. 10- 5mol..L- 1 and 10- 5mol..L- 1 corresponding to maximum metamorphosis rates of 67. 4% , 52. 2% and 43. 0% respectively. Most metamorphosis occurred in the period of 12- 24 h. Over 85% of larvae metamorphosed without attachment . NE can be deprived of its inductive activity when oxidized in seawater to be orange/ brown substances. Exposure time has signif icant inf luence on metamorphosis induction. NE produced the highest metamorphosis rate w ithin 2h, and effect ive concentration was inversely proportional to time in the range of 5 .. 10 - 6 mol..L - 1 ~ 5 .. 10 - 4 mol..L - 1 during this short period. L- DOPA brought about the maximum rate within 30min in the range of 5 .. 10 - 6 mol..L - 1 ~ 10 - 5 mol..L - 1 . A 5 min exposure to 10 - 5 mol.. L - 1 ~ 10 - 4 mol..L - 1 L- DOPA may enhance metamorphosis through attachment. Comparison of induct ive effect between artif icial inducers and chemical active substances ( CAS) that CAS is more active. NE- induced postlarvae well survived in low salinity but badly in high salinity.