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Juliana M. Santana Adriana Dos Reis Patrícia C. Teixeira Fábio C. Ferreira Cláudia M. Ferreira 《Journal of environmental science and health. Part. B》2013,48(12):896-900
In order to avoid that contaminated frog farms animals escaping in the environment and become potential vector of emergent diseases, studies with disinfection protocol are strictly necessary. The formaldehyde is one of the compounds tested in fungal disinfection protocols and also used in aquaculture. This study aimed to determine the median lethal concentration (LC50–96h) of formaldehyde in bullfrog tadpoles and to evaluate the possible genotoxic effects in acute exposition. Accordingly, the animals were exposed to formaldehyde in the concentrations of 6, 9, 12, 15, and 18 mg L?1, and after 96 h blood samples were drawn for the micronucleus (MN) test. The LC50–96h was 10.53 mg L?1, and the MN frequency increased in proportion to the formaldehyde concentrations, with an estimated frequency in the negative control being 1.35 MN/individual. We concluded that formaldehyde is genotoxic to tadpoles of bullfrogs in the tested concentrations, and the choice of this chemical should be contemplated before its use in animals in captivity. 相似文献
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Barbara A. Han Paul W. Bradley Andrew R. Blaustein 《Behavioral ecology and sociobiology》2008,63(2):241-250
Behaviors have evolved in response to various selection pressures over evolutionary time. However, not all behaviors are adaptive.
Some presumably “ancient” behaviors, persistent for millions of years, may be detrimental in the face of novel selection pressures
in modern times. These pressures include a multitude of emerging infectious diseases which may be stimulated by environmental
changes. We examined how a globally emerging amphibian pathogen, Batrachochytrium dendrobatidis (BD), affected two key evolutionarily persistent behaviors displayed by amphibian larvae: aggregation and thermoregulation.
Larval aggregation behavior is often essential for foraging, thermoregulation, and antipredator defense, but varies among
species. Thermoregulatory behavior speeds larval development in ephemeral habitats. Specifically, we examined whether aggregation
and thermoregulatory behaviors changed when exposed to the BD pathogen in two species (Bufo boreas and Rana cascadae) whose larvae aggregate in nature. In laboratory choice tests, larvae of neither species avoided infected conspecifics. BD-exposed
B. boreas larvae aggregated, while unexposed R. cascadae larvae associated more frequently with BD-exposed conspecifics. There was no evidence of behavioral fever or altered thermoregulation
in larvae of four species we examined (Pseudacris regilla, Rana aurora, B. boreas, R. cascadae). The absence of behavioral fever may suggest an inability of the larvae of some host species to mediate infection risk by
this pathogen. Thermoregulatory behaviors may exhibit a high degree of evolutionary inertia in amphibian hosts because they
are linked with host physiology and developmental rates, while altered aggregation behaviors could potentially elevate pathogen
transmission rates, leading to increased infection risk in social amphibian species. 相似文献
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