Effects of atrazine on vitellogenesis, steroid levels and lipid peroxidation, in female red swamp crayfish Procambarus clarkii.

Atrazine, a widely use herbicide, has been classified as a potential endocrine disruptor, especially for freshwater species. In this study, we tested the hypothesis that atrazine can affect reproduction in crayfish through dysregulation of vitellogenin expression and hormone synthesis. Adult female crayfish (Procambarus clarkii) were exposed during one month to atrazine at concentrations of either 1 or 5 mg/L.

Dietary lipid saturation influences environmental temperature preference but not resting metabolic rate in the Djungarian Hamster (Phodopus sungorus).

Heterothermic rodents increase self-selection of diets rich in polyunsaturated fatty acids (PUFAs) when exposed to cold, short days, or short-day melatonin profiles, and Djungarian hamsters (Phodopus sungorus) do so in long days in response to cold exposure alone. To determine whether Djungarian hamsters are also capable of selecting a thermal environment in response to dietary lipid composition, continuously normothermic hamsters were fed either a PUFA-rich diet or a diet rich in saturated fatty acids (SFAs) for 6-10 wk and given a choice of thermal environments. As predicted, SFA-fed hamsters were more likely than PUFA-fed hamsters to occupy the single heated corner of their cage ([Formula: see text]) and were most likely to show this diet-related difference in behavior when T(a) fell within the thermal neutral zone.

Effects of glyphosate and polyoxyethylenamine on growth and energetic reserves in the freshwater crayfish Cherax quadricarinatus (Decapoda, Parastacidae).

Freshwater crayfish Cherax quadricarinatus have a high commercial value and are cultured in farms where they are potentially exposed to pesticides. Therefore, we examined the sublethal effects of a 50-day exposure to glyphosate acid and polyoxyethylenamine (POEA), both alone and in a 3:1 mixture, on the growth and energetic reserves in muscle, hepatopancreas and hemolymph of growing juvenile crayfish. Exposure to two different glyphosate and POEA mixtures caused lower somatic growth and decreased muscle protein levels.

Atrazine is an immune disruptor in adult northern leopard frogs (Rana pipiens).

Atrazine, the most widely used herbicide in the United States, has been shown in several studies to be an endocrine disruptor in adult frogs. Results from this study indicate that atrazine also functions as an immune disruptor in frogs. Exposure to atrazine (21 ppb for 8 d) affects the innate immune response of adult Rana pipiens in similar ways to acid exposure (pH 5.

The influence of ambient temperature and the energy and protein content of food on nitrogenous excretion in the Egyptian fruit bat (Rousettus aegyptiacus).

The diets of frugivorous and nectarivorous vertebrates contain much water and generally have high energy but low protein contents. Therefore, we tested the prediction that to save energy under conditions of high energy demands and high water intake, frugivorous Egyptian fruit bats (Rousettus aegyptiacus) will increase both the absolute quantity and the proportion of ammonia in their urine. We also examined whether such changes occur when protein intake is low and water intake is high.

Acid exposure is an immune disruptor in adult Rana pipiens.

Acidic environments are physiological stressors for amphibians. The objective of the present study was to document the effect of an acidic environment on innate immune system function under controlled experimental conditions in Rana pipiens. We developed an in vivo assay, by injecting a suspension of 1-microm fluorescent beads in fluid thioglycollate, to induce peritonitis.

Oxalate, calcium and ash intake and excretion balances in fat sand rats (Psammomys obesus) feeding on two different diets.

Fat sand rats Psammomys obesus feed exclusively on plants of the family Chenopodiaceae, which contain high concentrations of chloride salts (NaCl, KCl) and oxalate salts. Ingestion of large quantities of oxalate is challenging for mammals because oxalate chelates Ca(2+) cations, reducing Ca(2+) availability. Oxalate is a metabolic end-point in mammalian metabolism, however it can be broken-down by intestinal bacteria.

Effects of acid stress in adult Rana pipiens.

The decline in frog populations is a well-recognized worldwide phenomenon and infectious disease has been implicated as a major cause in the global decline of amphibian populations. Rana pipiens are disappearing from many habitats where they used to flourish, and environmental acidification has been considered as a possible contributor to this disappearance. We present a model that integrates the results of several experiments on the effects of acid exposure on natural resistance and mortality of adult Rana pipiens.