Natural dissolved humic substances increase the lifespan and promote transgenerational resistance to salt stress in the cladoceran Moina macrocopa

摘要

Purpose Evidence has accumulated that humic substances (HS) are not inert biogeochemicals. Rather, they cause stress symptoms and may modulate the life history of aquatic organisms. Nevertheless, it is still not clear how HS interact with additional stressors and if their effects are transgenerational. We tested the interactive effects of HS and salt to cladocerans, discussing their consequences for the persistence in fluctuating environments, such as coastal lagoons. Methods We used life-table experiments to test the effects of natural HS from a polyhumic coastal lagoon (0, 5, 10, 20, 50, and 100 mg dissolved organic carbon (DOC) L~(-1)) on the life-history of the cladoceran Moina macrocopa. We further tested the effects of HS (10 mg DOC L"1), within and across generations, on the resistance of M. macrocopa to salt stress (5.5 gL~(-1)).