Toxic Effects And Mechanisms Of Alexandrium Species On Embryo Of Marine Shellfish And Moina Mongolica

In this paper, we investigated the effect and toxic mechanisms of the representative HABs-species——Alexandrium species on eggs-hatching success of Argopecten irradians Lamark, Meretrix meretrix Linnaeus, Ostrea gigas Thunberg, and life activities of Moina mongolica Daday. Moreover, we studied comparatively the effect of species which caused the large-scale blooms in East China Sea on eggs-hatching success of Ruditapes philippinarum (Adams et Reeve), and population growth of M. mongolica.The results showed, eight strains of PSP-produced A. tamarense (ATHK, AT5-1, AT5-3, ATCI02, ATCI03), A. catenella, A. lusitanicum and A. minutum and two strains of non-PSP-producer A. affine (AC-1, AS-1) had significantly detrimental effects, which indicated that it was a common feature of Alexandrium species that produced other than PSP toxins responsible for fertilized-egg hatching failure. The dissolved PSP toxins standard saxitoxin (STX) had no such inhibition on egg-hatching success, which further implied that fertilized-egg hatching failure was related to other non-PSP toxins.A. affine AC-1, which was non-PSP producer, had significantly effects on fertilized-egg hatching of A. irradians, M. meretrix and O. gigas; Algal culture, re-suspended cells, free-cell medium, and cell content of A. affine AC-1 all had markedly adverse impacts on their egg-hatching success. A. affine AC-1 destroyed cellular ultrastructure of their trochophore larvae, damaged cellular membrane structure and cytoplasm structure, and influenced functions of cellular organs, such as lysosomal stability, or made yelk granule in cells became atrophied; especially, A. affine AC-1 showed rather strong toxic effect on embryos of M. meretrix and O. gigas: when exposed to 3000cells·ml^-1 of A. affine AC-1 culture, all of embryos were dissolved,; and after exposed to 2000cells·ml^-1 of A. affine AC-1 culture for 2h, defensive membrane of the trochophore larvae were damaged and dissolved, and larvae became naked and looked as if a strand of grape. It is thereby very likely that...