title: Oil sands process-affected water impairs feeding by Daphnia magna.
abstract: Growth in extraction of bitumen from oil sands has raised concerns about influences of this industry on surrounding environments. Water clearance rate (a surrogate of feeding rate by Daphnia magna) in water containing D. magna exposed to oil sands process-affected water (OSPW) and its principal components, dissolved component (DC) and suspended particulate matter (SPM), was reduced to 72, 29, and 59% of controls, respectively. This study also examined several possible mechanisms for the observed changes algal cell density (i.e., feeding rate). There was no change in the digestive enzymes trypsin or amylase when D. magna were exposed to DC or SPM; however, exposure to total OSPW reduced trypsin activity. Mandible rolling or post-abdominal rejections, which are indicators of feeding and palatability of food, were not affected by any exposures to OSPW. Beating of thoracic limbs, which provides water flow toward the feeding groove, was reduced by exposure to SPM or total OSPW. Peristaltic activity was reduced by exposure to DC, which then might result in reduced digestion time in D. magna exposed to DC, SPM or whole OSPW. All treatments caused an increase in numbers of intact algae cells in the hindgut and excreted material. These results suggest that both DC and SPM affect feeding of D. magna by impairing actions of the digestive system, but most probably not by reducing rates of ingestion.
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada. Electronic address: e.lari82@gmail.com.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Lari
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
authors.forename: Dylan
authors.initials: D
authors.lastname: Steinkey
authors.affiliation: Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada.
authors.forename: Garrett
authors.initials: G
authors.lastname: Morandi
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Rasmussen
authors.affiliation: Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada; Department of Zoology, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824, USA; School of Biological Sciences, University of Hong Kong, Hong Kong, China.
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
authors.forename: Greg G
authors.initials: GG
authors.lastname: Pyle
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003621:Daphnia / Q000187:drug effects* / Q000378:metabolism; D004063:Digestion / Q000187:drug effects*; D004064:Digestive System / Q000187:drug effects*; D004435:Eating / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D008962:Models, Theoretical; D061329:Oil and Gas Fields; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Digestive enzyme; Mandible rolling; Nutrition; OSPW; Peristalsis; Thoracic limbs