Toxicity Test Assay of Waterborne Methylmercury on the Japanese Flounder (Paralichthys olivaceus) at Embryonic-Larval Stages

Effects of Short Term Methylmercury Exposure on Growth and Development of the Large Yellow Croaker Embryos and Larvae

“…The present study showed that the 48-h LC 50 value of MeHg (28.39 µg L −1 ) to embryos of large yellow croaker was generally lower than fathead minnow (Pimephales promelas, 71 µg L −1 ; Devlin, 2006), killifish (Fundulus heteroclitus, 50 µg L −1 ; Sharp and Neff, 1982), zebrafish (Danio rerio, 90 µg L −1 ; Cambero and Calvo, 2010) and coho salmon (Oncorhynchus kisutch, 54-71 µg L −1 ; Devlin and Mottet, 1992), but higher than the Japanese flounder (Paralichthys olivaceus, 15.3 µg L −1 ; Ren et al, 2019). While the 48-h LC 50 (18.27 µg L −1 ) and 96-h LC 50 (9.28 µg L −1 ) values of MeHg to large yellow croaker larvae was much Frontiers in Marine Science | www.frontiersin.org ;Wobeser, 1975;Mozhdeganloo et al, 2015), blue gourami (Trichogaster trichopterus, 48-h LC 50 , 94 µg L −1 , 96h LC 50 , 89 µg L −1 ; Roales and Perlmutter, 1974) and Japanese flounder (48-h LC 50 , 20.7 µg L −1 , 96-h LC 50 , 16.3 µg L −1 ).…”

“…On the other hand, when conducting indoor controlled experiments, different studies often set different experimental conditions depending on the species tested. Due to the confounding effects of experimental conditions, there are some controversies about the sensitivity of different species to toxicants (Ren et al, 2019). External environmental factors such as temperature, salinity, hardness, pH and DOC could greatly affect the toxicity of MeHg to fish (Pack et al, 2014).…”

“…However, there are some opposite phenomena. For example, Japanese flounder embryos are more sensitive than larvae when exposed to heavy metals such as mercury and cadmium (Huang et al, 2010;Ren et al, 2019). For such species, the chorions during early embryogenesis may have not yet hardened to function as barriers to effectively protect the embryos from exposure to toxicants (Herrmann, 1993).…”

“…For such species, the chorions during early embryogenesis may have not yet hardened to function as barriers to effectively protect the embryos from exposure to toxicants (Herrmann, 1993). Additionally, the chorions during late embryogenesis will gradually break and thereby increase the susceptibility of the embryos to waterborne toxicants (Ren et al, 2019). Therefore, the sensitivity of embryos to toxicants could be related to the processes by which the chorions biologically function in response to the waterborne toxicants entering the embryos (Sharp and Neff, 1982).…”

“…Early life stages (ELSs) of fish are extremely sensitive to contaminants, low concentrations of contaminants may not be sufficiently poisonous to adult fish but it can cause harmful impacts on embryos and larvae (Jezierska et al, 2009). Numerous studies have confirmed that MeHg has adverse effects on the early development of fish, leading to growth retardation, increased mortality, impaired cardiac function, morphological abnormalities, genetic, and protein expression disorders (Hassan et al, 2012;Wu et al, 2018;Ren et al, 2019).…”