In vivo visualization assay to evaluate the effects of maternal exposure to mercury on offspring bioaccumulation in the oriental river prawn (Macrobrachium nipponense)

Abstract

Mercury (Hg) is a persistent pollutant that accumulates in aquatic animals. However, studies related to understand how gonad tissue of this species responds to mercury exposure and elucidation of mercury bioaccumulation in crustacean offspring by cross-generational, are still sparse. The present study aimed to assess the bioaccumulation of Hg2+in vivo in prawn offspring by a specific aggregation-induced emission fluorogen (AIEgen). The 96 h median lethal concentration (LC50) values of mercury to the juveniles were 0.072 mg/L. Hg2+ reduced growth performance, damaged oocyte quality, and inhibited ovary maturation, thus inhibiting gonadal maturation in intact prawns. F1 offspring were exposed to Hg2+ by direct transfer from their F0 parents, as shown by the distribution of mercury in gonads and fertilized eggs. In the medium containing oriental river prawn larvae, the Hg2+ concentration decreased rapidly, indicating fast initial larval uptake of Hg2+. Due to metal ion triggered AIE activity, analysis of fluorescence images showed that prawn offspring accumulated Hg2+ via maternal transfer, and there was a relationship among the photoluminescence intensity, the AIEgen concentration, and mercury levels. The quantitative detection of Hg2+ absorption from prawn larvae by the AIEgen represents a novel analytical technique to understand the dynamics of Hg2+ between maternal and offspring.