Transgenerational impairments of reproduction and development of the marine invertebrate Crepidula onyx resulted from long-term dietary exposure of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)

Polybrominated diphenyl ethers have become ubiquitous in the environment and elevated concentrations have often been found in marine organisms. Using the gastropod Crepiduia onyx as a study model, this multigenerational study sets out to test the hypotheses that 1) parental dietary exposure to environmentally realistic levels of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) would lead to trans-generational impairments on fitness traits of marine invertebrates, and 2) the organisms might develop adaptation/acclimation after exposure for one or more generations. F-0 generation of C. onyx was fed with the dinoflagellate Isochrysis galbana encapsulated with two concentrations of BDE-47 (1.78 and 16.0 ng million cells(-1), respectively), and half of the F-1 offspring from the higher concentration treatment was returned to control condition (transgenerational group), while the other half received BDE-47 treatment continuously (continuous treatment group). Bioaccumulation and maternal transfer of BDE-47 were evident in all life stages of the F-0 generation and in F-1 eggs, respectively. Exposure to BDE-47 reduced fecundity, delayed sexual maturity, and impeded embryonic development in F-0 to F-2. In particular, developmental toxicity of F-2 embryos was apparent in the transgenerational group, but not in the continuous treatment group, even when BDE-47 was not detected in the F-2 embryos nor in their mothers and they have never been exposed to the chemical. This study also suggested that the offspring might have developed adaptation/acclimation to the exposure of BDE-47 within two generations of exposure, and that the physiological alterations associated with acclimation/adaptation might have hindered the normal larval development under a stress free condition. These findings highlighted the need for long-term multigenerational studies in the ecological risk assessment of chemicals alike. (C) 2017 Elsevier Ltd. All rights reserved.