title: Effects of atrazine on egg masses of the yellow-spotted salamander (Ambystoma maculatum) and its endosymbiotic alga (Oophila amblystomatis).
abstract: Embryonic growth of the yellow-spotted salamander (Ambystoma maculatum) is enhanced by the presence of the green alga Oophila amblystomatis, in the egg capsule. To further assess potential impacts of herbicides on this relationship, A. maculatum egg masses were exposed to atrazine (0-338 μg/L) until hatching (up to 66 days). Exposure to atrazine reduced PSII yield of the symbiotic algae in a concentration-dependent manner, but did not significantly affect visible algal growth or any metrics associated with salamander development. Algal cells were also cultured in the laboratory for toxicity testing. In the 96-h growth inhibition test (0-680 μg/L), ECx values were generally greater than those reported for standard algal test species. Complete recovery of growth rates occurred within 96-h of transferring cells to untreated media. Overall, development of A. maculatum embryos was not affected by exposure to atrazine at concentrations and durations exceeding those found in the environment.
authors.affiliation: Centre for Toxicology, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: Leilan
authors.initials: L
authors.lastname: Baxter
authors.affiliation: Syngenta Crop Protection, LLC, Greensboro, NC, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Brain
authors.affiliation: Syngenta Crop Protection, LLC, Greensboro, NC, USA.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Hosmer
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
authors.forename: Mohini
authors.initials: M
authors.lastname: Nema
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Müller
authors.affiliation: Centre for Toxicology, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: Keith R
authors.initials: KR
authors.lastname: Solomon
authors.affiliation: Department of Environment and Geography, University of Manitoba, Winnipeg, MB R3T 2N2, Canada. Electronic address: mark.hanson@umanitoba.ca.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Hanson
mesh_terms: D000557:Ambystoma / Q000196:embryology*; D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D000460:Chlorophyta / Q000187:drug effects* / Q000502:physiology; D006540:Herbicides / Q000633:toxicity*; D010063:Ovum / Q000187:drug effects* / Q000254:growth & development; D013559:Symbiosis / Q000187:drug effects*; D018675:Toxicity Tests
chemical_list: D006540:Herbicides; D001280:Atrazine
keywords: Algae; Ambystoma maculatum; Atrazine; Endosymbiont; Herbicide; Oophila; Salamander