Immune responses of Octopus vulgaris (Mollusca: Cephalopoda) exposed to titanium dioxide nanoparticles

Intramuscular injections of titanium dioxide nanoparticles (nTiO2) at two concentrations (1 and 10 mg/kg) induced short-term immune response in the cephalopod mollusk Octopus vulgaris. The number of circulating hemocytes, lysozyme activity and the concentration of nitric oxide (NO) detected in the hemolymph of treated octopuses increased significantly 4 h after injections. The effects on NO were dose dependent. The observed values were back to their baseline 24 h later. No other effects were observable at longer intervals (4 days).