The Research Of Settlement And Metamorphosis Of Crassostrea Hongkongensis Eyespots Larval In Different Attached Substrate, Metal Ion (K⁺, Cu²⁺),L-Dopa And NE

In this paper, the settlement and metamorphosis effect of Crassostrea hongkongensis eyespots larva in different attached substrate, two kinds of metal ion (K+, Cu2+) and L-3,4-dihydroxyphenylalanine (L-DOPA), norepinephrine (NE) was studied. The main results of this thesis are summarized as follows:1. The highest of settlement rate was49.85%in the black polyethylene film, followed by black plastic board (19.33%), and the lowest was red plastic board (5.14%).2. Adding K+had induced the settlement and metamorphosis of eyespots larva, when adding13.42mmol/L K+disposing24h, larval settlement increasing rate and metamorphosis increasing rate reached42.39%and25.20%respectively compared with the control.3. While adding Cu2+had no effect, with the increase of Cu2+processing time and concentration, the mortality rate of C. hongkongensis eyespots larva obviously enhanced which suggested that excessive levels of Cu2+are toxic to C. hongkongensis eyespots larvae.4. Adding L-DOPA and NE had effect to induce the metamorphosis of larval, but NE of oyster induction effect was better than L-DOPA. When adding different concentration of L-DOPA and NE continuous exposure the larval of C. hongkongensis after12h,24h and48h, the optimum induction concentration of L-DOPA and NE were respectively10-5mmol/L and10-4mmol/L with exposuring24h, the larval of C. hongkongensis metamorphosis rate were45.25%and57.14%, respectively; When adding L-DOPA and NE exposure the larval of C. hongkongensis1h and24h after cultivating for24h, the induced maximum metamorphosis rate in continuous24h after cultivating for24h, the larval of C. hongkongensis. metamorphosis rate were65.36%and67.84%, respectively.