Effects of salinity and turbidity on development of bamboo sole (Heteromycteris japonicus)

Abstract

— Heavy rain can decrease salinity and increase turbidity of the water in coastal areas, negatively affecting the development of organisms, par- ticularly during their early life stages. In this study, the effects of salinity and turbidity on embryos of the bamboo sole ( Heteromycteris japonicus ) were evalu- ated to improve understanding of its tolerance to global climate change. Three experiments were carried out over a 7- d period. In the first experiment, embryos of bamboo sole were exposed for 3 h to 1 of 6 salinity levels (14–34). Low salinity levels (14 and 18) resulted in signifi- cantly shorter total lengths of newly hatched larvae in comparison with larval sizes in treatments with higher salinities, but no significant differences were observed in hatching rate and larval survival rate among treatments. In the second experiment, embryos were exposed to turbidities of 0, 100, 300, 500, and 700 nephelometric turbidity units for 3 h. Turbidity significantly decreased hatching rate, survival rate, and total length and increased onset hatching time and percentage of abnormality. In the third experiment, embryos were exposed to different combinations of salinity and turbidity. The interaction effect of salinity and turbidity on total length of newly hatched larvae was significant. These findings indicate that embryo development of bamboo sole was more affected by