title: Ontogenic delays in effects of nitrite exposure on tiger salamanders (Ambystoma tigrinum tigrinum) and wood frogs (Rana sylvatica).
abstract: Under certain conditions, nitrite can be present in freshwater systems in quantities that are toxic to the fauna. I exposed wood frog (Rana sylvatica) and eastern tiger salamander (Ambystoma tigrinum tigrinum) embryos and young tadpoles and larvae to elevated concentrations of nitrite in chronic toxicity tests: 0, 0.3, 0.6, 1.2, 2.1, 4.6, and 6.1 mg/L NO2-N, exposing individuals as both embryos and larvae. Nitrite caused significant declines in wood frog hatching success (3.4 mg/L NO2-N, wood frog), and lower concentrations caused significant mortality during the early larval stages (4.6 mg/L NO2-N, salamander; 0.5 mg/L NO2-N, wood frog). Later tests exposing individuals to nitrite only after hatching showed that both wood frog and tiger salamander vulnerability to nitrite declined shortly after hatching. Hence, examining a single life-history stage, especially later in development, may miss critical toxic effects on organisms, causing the researcher potentially to underestimate seriously the ecological consequences of nitrite exposure.
authors.affiliation: Department of Biology, Syracuse University, 130 College Place, Syracuse, New York 13244, USA. klgriffi@syr.edu
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Griffis-Kyle
mesh_terms: D000557:Ambystoma / Q000254:growth & development*; D000818:Animals; D005618:Fresh Water; D007814:Larva / Q000254:growth & development; D009573:Nitrites / Q000633:toxicity*; D011898:Ranidae / Q000254:growth & development*
chemical_list: D009573:Nitrites