Inhibition of feeding and reproduction in benthic copepod Tigriopus japonicus exposed to oil dispersed sediments and its antioxidant responses

Abstract

Accidental oil spill causes ecological risks in aquatic environment. Particularly, oil attached to sediments has received great concern because effective technologies and equipment to remove oil from fine grains have not been developed yet. The copepod Tigriopus japonicus is one of the great candidates as a bio-indicator species, as they have short life cycle and diverse end-points can cover molecular to individual levels. In particular, this species can be directly affectedby polluted sediment as it is benthic copepod. In this study, copepod T. japonicus was exposed to oil dispersed sediments (<75&#61549 m grain size) and its biological repercussions were measured to evaluate the potency of the marine copepod T. japonicus as an experimental species for oil contaminated sediments. Adult and nauplius of T. japonicus were exposed to oil polluted sediments. In exposure group, molecular responses (antioxidant genes) were detected caused by oil dispersed sediments. For nauplius, growth retardation was measured at their nauplius stages in test group for 10 days exposure. For adult T. japonicus, survival rate was not observed but their reproduction rate (number of ovigerous female andtheir hatching success) was significantly reduced. The inhibition of assimilation rate was also tested separately using 13C labeled phytoplankton as a diet. This study showed diverse end-points of T. japonicus can be markers for oil dispers The copepod Tigriopus japonicus is one of the great candidates as a bio-indicator species, as they have short life cycle and diverse end-points can cover molecular to individual levels. In particular, this species can be directly affectedby polluted sediment as it is benthic copepod. In this study, copepod T. japonicus was exposed to oil dispersed sediments (<75&#61549 m grain size) and its biological repercussions were measured to evaluate the potency of the marine copepod T. japonicus as an experimental species for oil contaminated sediments. Adult and nauplius of T. japonicus were exposed to oil polluted sediments. In exposure group, molecular responses (antioxidant genes) were detected caused by oil dispersed sediments. For nauplius, growth retardation was measured at their nauplius stages in test group for 10 days exposure. For adult T. japonicus, survival rate was not observed but their reproduction rate (number of ovigerous female andtheir hatching success) was significantly reduced. The inhibition of assimilation rate was also tested separately using 13C labeled phytoplankton as a diet. This study showed diverse end-points of T. japonicus can be markers for oil dispers