title: Natural organic matter alters size-dependent effects of nanoCuO on the feeding behaviour of freshwater invertebrate shredders.
abstract: Nanoparticle size and the presence of natural organic matter (NOM) may influence the toxicity of nanoCuO to aquatic biota, but their interactive effects have been poorly investigated. We examined the feeding behaviour of the invertebrate shredder Allogamus ligonifer when exposed to sublethal concentrations of nanoCuO (50 and 100 mg L(-1)) with three particle sizes (12, 50 and 80 nm) in the absence or presence of humic acid (HA, 100 mg L(-1)) as a proxy of NOM. We further examined the ability of invertebrates to recover from the stressors. In the absence of nanoCuO and HA, the feeding rate of shredders was 0.416 mg leaf DM mg(-1 )animal DM day(-1). The exposure to increased nanoCuO concentrations inhibited the feeding rate and effects were stronger as nanoparticle size decreased (up to 83.3% inhibition for 12 nm particles). The exposure to HA alone inhibited the feeding activity by 52.7%. However, the co-exposure to nanoCuO and HA alleviated the inhibitory effects promoted by smaller and medium sized nanoCuO (up to 29.5%). The recovery of feeding activity by the shredders after stress removal was very low; maximum recovery (16.7%) was found for invertebrates rescued from pre-exposure to lower concentration of nanoCuO with larger size.
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
authors.forename: Arunava
authors.initials: A
authors.lastname: Pradhan
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Geraldes
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
authors.forename: Sahadevan
authors.initials: S
authors.lastname: Seena
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Pascoal
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal. Electronic address: fcassio@bio.uminho.pt.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Cássio
mesh_terms: D000818:Animals; D003300:Copper / Q000633:toxicity*; D005247:Feeding Behavior / Q000187:drug effects*; D005618:Fresh Water; D007448:Invertebrates / Q000502:physiology*; D053758:Nanoparticles / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper; C030973:cupric oxide
keywords: Feeding behaviour; Humic acid; Invertebrate shredders; NanoCuO size; Stress recovery