title: Study design, water quality, morphometrics and age of the bullfrog, Rana catesbeiana, in sub-watersheds of the Yamaska River drainage basin, Québec, Canada.
abstract: The Yamaska River basin is renowned for its poor water quality, which has been attributed to intensive agriculture (corn, soya, high-density pork and poultry production). Six locations within the Yamaska watershed were selected to evaluate the impact of agriculture on water habitats and study the bullfrog as a sentinel species of potential exposure and effects. The selected sub-watersheds were chosen according to the percentage of surface area under cultivation and classified as low (0-19%), moderate (20-59%) or high (>60%). In 2004 and 2005, analysis of surface water samples demonstrated that pesticide concentrations and most water quality parameters increased with increasing agricultural activity. Sixteen adult bullfrogs were sampled from each site. Animals were weighed, measured for length (total, snout-vent, tibia, tympanum), sexed, and evaluated for the colour of the throat. Skeletochronology was used to estimate the growth and age of the frogs. Cross-sections of decalcified phalanges and femurs were treated in order to count LAGs (lines of arrest growth) and for the observations of other parameters related to bone growth. The bullfrogs from highly contaminated sites had the lowest mean age and the smallest snout-vent length compared to sites of low contamination.
authors.affiliation: TOXEN Research Centre, Université du Québec at Montréal, Case Postale 8888, Succursale Centre-ville, Montréal, Québec H3C 3P8, Canada.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Spear
authors.forename: Monique
authors.initials: M
authors.lastname: Boily
authors.forename: Isabelle
authors.initials: I
authors.lastname: Giroux
authors.forename: Christian
authors.initials: C
authors.lastname: Deblois
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Leclair
authors.forename: Marc
authors.initials: M
authors.lastname: Levasseur
authors.forename: Raymond
authors.initials: R
authors.lastname: Leclair
mesh_terms: D000367:Age Factors; D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology; D004784:Environmental Monitoring; D005260:Female; D008297:Male; D010573:Pesticide Residues / Q000032:analysis; D011792:Quebec; D011892:Rana catesbeiana / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010573:Pesticide Residues; D014874:Water Pollutants, Chemical