福建牡蛎成贝及幼贝对低盐胁迫耐受性分析OA北大核心CSCDCSTPCD

To explore the tolerance of Crassostrea angulata to low-salinity stress,this study systematically ana-lyzed the effects of low-salinity stress on the survival,reproductive capacity,hemolymph osmoregulation,and gill tissue structure of adult and juvenile oysters by setting up a salinity gradient.The results indicated significant dif-ferences in the tolerance levels of C.angulata across developmental stages.For adults,the 7-day median lethal sa-linity(LS₅₀)was 13.5,with a sublethal salinity threshold of 19;for juveniles,these respective values were 9.5 and 14,indicating that juveniles were more tolerant.Salinity below 14 severely inhibited fertilization and hatching;the optimal salinity range for reproduction was 23-27.The hemolymph osmotic pressure equalized with that of the en-vironment within 12 h of stress exposure,suggesting that this species is a typical osmoconformer.Long-term low-salinity stress damaged gill tissues,which manifested as a widening of the interlamellar space,swelling of ap-ical cells,and detachment of cilia.This study clarifies the low-salinity tolerance limits of C.angulata at different life stages and the underlying physiological response mechanisms.It provides a scientific basis for healthy aqua-culture,germplasm resource protection,and disaster prevention and control in estuarine and coastal areas.