The Humboldt upwelling system off the Peruvian coasts presents scenarios of hypoxia and eventual H2S production. Argopecten purpuratus, a commercially important bivalve, is tolerant to hypoxia, although the effect of sulfide can be lethal. Thus, the aim of this study was to evaluate the recovery capacity of A. pupuratus in the presence of hypoxia and hypoxia+H2S.
Three treatments: control, hypoxia, and hypoxia+H2S; and two experimental phases: exposure and recovery, were established. Gill tissues were collected from the control organisms on day two of exposure and at the end of recovery for differential expression analysis based on transcriptome. Mortality was evaluated during both phases, and a survival curve was constructed using the Kaplan Meier model to evaluate recovery capacity from the point of no return (PNR50). Genes overexpression was observed related to catabolic processes in response to hypoxia, to apoptosis and necrosis in response to hypoxia+H2S, as well as genes related to DNA repair mechanisms in the recovery phase. The PNR50 in hypoxia was 3 days, while in hypoxia+H2S was 2.5 days (p>0.05 Chi-square).
We concluded that combined exposure to hypoxia and H2S negatively affects the recovery capacity of A. purpuratus compared to hypoxia alone, although without significant differences. In addition, ten genes were identified as potential molecular markers for identifying exposure to hypoxia+H2S.