title: The bioaccumulation and effects of selenium in the oligochaete Lumbriculus variegatus via dissolved and dietary exposure routes.
abstract: Aquatic organisms take up selenium from solution and from their diets. Many questions remain regarding the relative importance of selenium accumulation from these sources and resulting effects in benthic invertebrates. The present study addressed the toxicity and accumulation of Se via dissolved and dietary exposures to three different Se species, in the freshwater oligochaete Lumbriculus variegatus. Worms were exposed to 20μg/g dry weight of selenite (Se(IV)), selenate (Se(VI)), or seleno-l-methionine (Se-Met) in their diet (sediment) or to 15μg/L dissolved Se in water-only exposures. While the dissolved and sediment Se levels differed greatly, such levels may co-occur at a Se-contaminated site. Se accumulation, worm population growth, lipid peroxidation (as TBARS), and Na(+)/K(+)-ATPase activity were quantified at the end of the 2-week exposure. The sediment Se-Met exposure caused 100% mortality, while worm densities were reduced by the other exposures except the Se(VI) one. Se bioaccumulation was generally higher for the sediment-Se exposure than the dissolved-Se ones, and was higher for Se(IV) than Se(VI) in the dissolved-Se exposure but not the sediment-Se one. The Se accumulation was highest for Se-Met. The oligochaetes that accumulated Se had higher levels of lipid peroxidation and reduced Na(+)/K(+)-ATPase activity. The present study's findings of differences in Se accumulation and toxicity for the three Se species, with effects generally but not exclusively a function of Se body burdens, underscore the need for research on these issues in invertebrates. Moreover, the results imply that the dietary uptake route is the predominant one for Se accumulation in L. variegatus.
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Liaoning 110016, PR China. Electronic address: xielt@iae.ac.cn.
authors.forename: Lingtian
authors.initials: L
authors.lastname: Xie
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Liaoning 110016, PR China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wu
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Liaoning 110016, PR China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Chen
authors.affiliation: Guangxi Academy of Fishery Science, Guangxi 530021, PR China. Electronic address: lfylzc123@163.com.
authors.forename: Yongju
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Guangxi Academy of Fishery Science, Guangxi 530021, PR China.
authors.forename: Zhongbao
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Division of Marine Chemistry, National Marine Environmental Monitoring Center, Dalian, Liaoning 116023, PR China.
authors.forename: Jingli
authors.initials: J
authors.lastname: Mu
authors.affiliation: Department of Biology, University of Louisiana at Lafayette, P. O. Box 43602, Lafayette, LA 70504-3602, USA.
authors.forename: Emmanuel R
authors.initials: ER
authors.lastname: Blankson
authors.affiliation: Inner Mongolia University for the Nationalities, Tongliao 028000, PR China.
authors.forename: Wu
authors.initials: W
authors.lastname: Dong
authors.affiliation: Department of Biology, University of Louisiana at Lafayette, P. O. Box 43602, Lafayette, LA 70504-3602, USA.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Klerks
mesh_terms: D000818:Animals; D004032:Diet; D004781:Environmental Exposure / Q000032:analysis*; D005618:Fresh Water / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism; D012643:Selenium / Q000378:metabolism / Q000633:toxicity*; D018036:Selenium Compounds / Q000378:metabolism / Q000633:toxicity; D012645:Selenomethionine / Q000378:metabolism / Q000633:toxicity; D012995:Solubility; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D018036:Selenium Compounds; D014874:Water Pollutants, Chemical; D012645:Selenomethionine; D012643:Selenium
keywords: Dietary and dissolved exposures; Lipid peroxidation; Lumbriculus variegatus; Na(+)/K(+)-ATPase; Selenium