Developmental abnormalities and neurotoxicological effects of CuO NPs on the black sea urchin Arbacia lixula by embryotoxicity assay

• The embryotoxicity of CuO NPs was evaluated in black sea urchin A. lixula embryos.
• Fertilized eggs were exposed to five doses of CuO NPs until pluteus larval stage.
• The embryotoxicity tests were conducted in 24-well plates.
• Developmental delay and skeleton abnormalities were observed.
• Neurotoxicological damage on cholinergic and serotonergic systems were observed.

The embryotoxicity of CuO NPs was evaluated in the black sea urchin Arbacia lixula embryos, by using 24-well plates. Fertilized eggs were exposed to five doses of CuO NPs ranging from 0.07 to 20 ppb, until pluteus stage. CuO NPs suspensions in artificial seawater formed agglomerates of 80–200 nm size, and copper uptake was 2.5-fold up in larvae exposed to high NP concentrations in respect to control. Developmental delay and morphological alteration, including skeletal abnormalities, were observed, as well as impairment in cholinergic and serotonergic nervous systems. These findings suggest the potential of CuO NPs to interfere with the normal neurotransmission pathways, thus affecting larval morphogenesis. Overall, the embryotoxicity tests are effective for evaluation of nanoparticle effects on the health of aquatic biota. Furthermore, as the black sea urchin A. lixula demonstrated to be vulnerable to NP exposure, it may be a valid bioindicator in marine biomonitoring and ecotoxicological programmes.