Sublethal Effects of Nitrite on Eastern Tiger Salamander (Ambystoma tigrinum tigrinum) and Wood Frog (Rana sylvatica) Embryos and Larvae: Implications for Field Populations

Abstract

Ephemeral pools, which can have high animal biomass and low dissolved oxygen, may be prone to nitrite accumulation. As such, it is important to understand how exposure to nitrite might affect development and growth of amphibians that breed in these ephemeral pools. Wood frog (Rana sylvatica) and eastern tiger salamander (Ambystoma tigrinum tigrinum) embryos and tadpoles and young larvae were exposed to elevated concentrations of nitrite derived from sodium nitrite: 0, 0.3, 0.6, 1.2, 2.1, 4.6, and 6.1 mg l -1 NO 2 -N. Increasing nitrite exposure slowed embryonic and larval development in both the eastern tiger salamander and the wood frog, reduced growth in tiger salamander embryos and larvae, and delayed metamorphosis in the wood frog. At concentrations less than 2 mg l -1 NO 2 -N nitrite delayed hatching, and at concentrations above 2 mg l -1 time to hatching decreased causing more individuals to hatch at less developed stages. Nitrite also increased asynchrony in tiger salamander hatching. The sublethal effects of nitrite on amphibian development, growth and hatching could have serious repercussions on amphibian fitness in ephemeral environments. Potential increases in mortality on field populations caused by sublethal effects of nitrite are discussed.

Intraspecific Differences in Responses of Marsh Frog (Pelophylax ridibundus) Tadpoles Exposed to Environmentally Relevant and Acute Levels of Ammonium Nitrate Fertilizer

“…Xu and Oldham (1 997), for example, used G32-G35 stage tadpoles, and Watt and Oldham (1995) used six-week old tadpoles, whereas we used seven-day old, G25 stage tadpoles. Furthermore, the difference in the level of interspecific resistance to nitrate was another reason for not observing any difference in duration of larval development (Hecnar 1995, Hamer et al 2004, Griffis-Kyle 2007, Griffis-Kyle and Ritchie 2007, Earl and Whiteman 2009. We also found differences in the duration of the larval development of the same species at the same tadpole stages when exposed to the same levels of NH4N03, indicating innate resistance probably due to previous experience of the population with NH4N03 at their natural sites.…”

Analysis of the Avoidance of Nitrogen Fertilizers in the Water Column by Juvenile Iberian Water Frog, Pelophylax perezi (Seoane, 1885), in Laboratory Conditions

“…Both aquatic and terrestrial amphibian phases are vulnerable to nitrogen excess in their environments (Hatch et al 2001;Marco et al 2001;Ortiz et al 2004;Griffis-Kyle 2007). Ammonium chloride and sodium nitrate are nitrogen compounds used as fertilizer (Bhandari et al 1971;Graebing et al 2002) since they are a source of ammonium and nitrate.…”

“…The presence of these ions in water may increase nitrite concentration as a consequence of bacterial activity (Atlas and Bartha 2002). All three forms of nitrogen have been shown to negatively (Jofre and Karasov 1999;Schuytema and Nebeker 1999;Griffis-Kyle 2007) or positively, by way of algal proliferation (Boone et al 2007) affect the survival, growth, and development of amphibian embryos and larvae. Nevertheless, no study has been performed on the effects of their excess on postmetamorphic amphibians in spite of the great importance that postmetamorphic stages may have on amphibian population dynamics, as it has been previously suggested (Biek et al 2002).…”

Efeitos letais e subletais da poluição por nitrogênio em larvas de anuros

“…Para os girinos, a redução do crescimento pode ter sérios efeitos negativos, porque as capacidades competitivas são prejudicadas e porque indivíduos menores são mais vulneráveis à predação (Berven, 1990;Newman & Dunham, 1994). Já a redução do desenvolvimento e, portanto o prolongamento do período larval pode reduzir a sobrevivência devido à dessecação em hábitats efêmeros e ao maior período de exposição aos predadores aquáticos (Griffis-Kyle, 2007). Da mesma forma, o tamanho corporal menor pode prejudicar a sobrevivência dos estágios pós-metamórficos e o sucesso reprodutivo dos adultos.…”

“…A redução do desenvolvimento larval também pode afetar negativamente os anfíbios devido à dessecação em hábitats efêmeros e ao maior período de exposição aos predadores aquáticos (Griffis-Kyle, 2007). E tanto a redução do crescimento quanto do desenvolvimento podem resultar em metamórficos com menor tamanho, o que também condiciona menor sobrevivência à predação (Xu & Oldham, 1997), menor tolerância à desidratação, e menor sucesso reprodutivo, pois adultos menores possuem menor fertilidade e sucesso na seleção de parceiros Goater et al, 1993).…”