Physiological responses of pacu (Piaractus mesopotamicus) to intermittent cold exposure: A comprehensive analysis of stress, immunity, antioxidant, and metabolic adaptations.

This study examined the energy-dependent physiological responses, including stress, innate immune, and antioxidant systems, as well as indicators of energy mobilization, in pacu (Piaractus mesopotamicus) exposed to intermittent cold, aiming to assess the correlations between these responses. The fish were acclimated to 28 °C, divided into two groups, a control group maintained at 28 °C, and another exposed to 16 °C for two 24 h periods with a 5-day interval between them. The fish were sampled at six time points: baseline (after acclimatization to 28 °C), 24 h after the 1st exposure to 16 °C, after 5 days of recovery at 28 °C, 24 h after the 2nd exposure to 16 °C, and after 24 and 48 h of recovery at 28 °C.

Acute low temperature and lipopolysaccharide differentially modulated the innate immune and antioxidant responses in a subtropical fish, the pacu (Piaractus mesopotamicus).

Exogenous factors such as low water temperature can be stressful and elicit negative immune system effects, especially for fish, which are ectothermic. Stress and immune responses require energy overload, which can affect the cellular redox balance, causing oxidative damage. These overall responses impair the animal's health and negatively affect fish farming.

Temperature, dietary lipids, and Aeromonas hydrophila modulate self-protection mechanisms in pacu Piaractus mesopotamicus Holmberg 1887.

Water temperature has a direct influence on several physiological processes in fish. This study investigated the effects of the exposure of pacu (Piaractus mesopotamicus) to 10 days of reduced temperature in stress and innate immune and antioxidant systems, all of which are involved in energy mobilization. Two groups of fish, fed a control diet or a diet with a higher lipid level, were exposed for 10 days to 16°C and then inoculated with Aeromonas hydrophila bacterin.

Frequency Tunable, Cavity-Enhanced Single Erbium Quantum Emitter in the Telecom Band.

Single quantum emitters embedded in solid-state hosts are an ideal platform for realizing quantum information processors and quantum network nodes. Among the currently investigated candidates, Er^{3+} ions are particularly appealing due to their 1.5  μm optical transition in the telecom band as well as their long spin coherence times.

Modulation of immunity and hepatic antioxidant defense by corticosteroids in pacu (Piaractus mesopotamicus).

We investigated the impact of both the oral administration of hydrocortisone (HC) and an acute stressor on stress, innate immune responses and antioxidant system/oxidative stress responses of juvenile Piaractus mesopotamicus. Fish were either 1) given a commercial feed (C), 2) given a feed supplemented with 400 mg/kg HC, or 3) fed a commercial feed, chased for 2 min and exposed to air for 4 min (S). After initial sampling, fish C and HC were fed and sampled 1, 3, 6, 24 and 72 h post-feeding.