title: Crude oil exposure affects air-breathing frequency, blood phosphate levels and ion regulation in an air-breathing teleost fish, Hoplosternum littorale.
abstract: Exposure of a facultative air breather, Hoplosternum littorale, to 12.5, 25, and 37.5% of the water soluble fraction (WSF) of Urucu crude oil, resulted in a rapid increase in air-breathing frequency (ABF) sustained over the 45 min period of exposure. Following 4 h exposure to a graded increase in WSF up to 50%, there was no significant affect on haematocrit, or plasma [Na+] and [K+]. Crude oil ingestion resulted in some degree of ion regulatory impairment, however results were variable. A single oral dose of 3.0 ml/kg of Urucu crude elevated net whole body Na+ efflux and resulted in a 7% reduction in plasma [Na+] 72 h following ingestion. A single oral dose of 3.0 ml/kg resulted in a significant net whole body K+ efflux and a reduction in plasma [K+] 24 h after ingestion. No mortalities were observed in any exposure regime in this study. An oral dose of Urucu crude oil at 3.0 ml/kg also resulted in a 24% reduction in ATP:Hb ratio (from 0.206 to 0.157) and a 31% reduction in GTP:Hb ratio (0.455 to 0.315) 24 h following ingestion indicating that these fish may be hypoxemic. Taken together, these results indicate that exposure of H. littorale to Urucu crude oil affects gas exchange and ion regulation.
authors.affiliation: Institute of Biology, Odense University, Denmark. braunerc@mcmaster.ca
authors.forename: C J
authors.initials: CJ
authors.lastname: Brauner
authors.forename: C L
authors.initials: CL
authors.lastname: Ballantyne
authors.forename: M M
authors.initials: MM
authors.lastname: Vijayan
authors.forename: A L
authors.initials: AL
authors.lastname: Val
mesh_terms: D000818:Animals; D005399:Fishes / Q000097:blood / Q000502:physiology*; D010578:Petroleum / Q000633:toxicity*; D010710:Phosphates / Q000097:blood*; D011188:Potassium / Q000097:blood / Q000378:metabolism*; D012119:Respiration / Q000187:drug effects*; D012964:Sodium / Q000097:blood / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D010578:Petroleum; D010710:Phosphates; D014874:Water Pollutants, Chemical; D012964:Sodium; D011188:Potassium