This study assessed the behavior of the aquatic snail Potamopyrgus antipodarum under a combination of four treatments: (1) animals normally fed (control treatment), (2) starved animals, (3) animals normally fed and exposed to a high conductivity, and (4) starved animals exposed to a high conductivity. Therefore, the study of the effects of starvation on baseline behaviors of invertebrates is a relevant issue. This could alter animal behavior, along with the toxicant. Among those parameters, starvation of animals is a factor that is usually applied in ecotoxicological short-term bioassays. However, abiotic and biotic parameters may interact causing changes in the behavioral responses.
The relevance of these parameters has caused a rise in their use in aquatic ecotoxicology. Our study contributes to the knowledge of the chronic effects of nitrate on the behaviour and reproduction of an aquatic snail.īehavioral endpoints are important parameters to assess the effects of toxicants and other stressors on natural ecosystems. Reproductive impairment was caused at realistic nitrate concentrations which is relevant to the risk assessment of this compound. Our results showed that nitrate did not cause mortality, but it reduced the velocity of movement (at 44.9, 81.8 and 156.1 mg N-NO(3) (-)/L) and number of live newborns (in all tested concentrations). Velocity was recorded using quantitative video monitoring. In each treatment, 12 animals were individually monitored for velocity (weekly) and newborn production (every 3-4 days). The aim of our study is to assess the effect of chronic (35 days) exposure to nitrate on the behaviour (velocity of movement) and reproduction (number of newborns) of the aquatic snail Potamopyrgus antipodarum. In spite of the toxicity of nitrate to aquatic animals, there are relatively few studies on the chronic toxicity of this compound to invertebrates. However, in the last decades, several human activities are the causes of the rising amounts of organic matter and inorganic nitrogen nutrients in aquatic ecosystems, causing notable increase of nitrate above background natural levels. Nitrate (NO(3) (-)) is present in aquatic ecosystems as a natural component of the nitrogen cycle.
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