“…In the present study, a zebrafish larva with morphologically abnormal development did not have an inflated swim bladder even at 72 hph, which suggests that abnormal larvae may not achieve swim bladder inflation. In zebrafish larvae, abnormal development is often induced not only by thyroid hormone‐disrupting chemicals but also by exposure to various other chemicals, such as broflanilide (Duan et al, 2021), ethylparaben (Merola et al, 2020), fluxapyroxad (Lin et al, 2021), linuron (Maharaj et al, 2020), propylparaben (Perugini et al, 2019), 4‐epianhydrotetracycline (Wang et al, 2020), and chlorinated anilines (Horie, Yamagishi, et al, 2017), which induce edema, body curvature, or non‐inflation of the swim bladder. Taken together with these studies, our results indicate that when zebrafish are used for in vivo assays to detect thyroid hormone‐disrupting activity, the test period is shorter compared with the use of Japanese medaka, but to evaluate the effect of chemical substances on swim bladder inflation, it is necessary to determine whether the effect is due to thyroid disturbance or abnormal embryo development.…”