Prior thermal acclimation gives White Sturgeon a fin up dealing with low oxygen

Conservation Physiology, Journal Year: 2025, Volume and Issue: 13(1)

Published: Jan. 1, 2025

Abstract Assessing how at-risk species respond to co-occurring stressors is critical for predicting climate change vulnerability. In this study, we characterized young-of-the-year White Sturgeon (Acipenser transmontanus) cope with warming and low oxygen (hypoxia) investigated whether prior exposure one stressor may improve the tolerance a subsequent through “cross-tolerance”. Fish were acclimated five temperatures within their natural range (14-22°C) month assessment of thermal (critical maxima, CTmax) hypoxia (incipient lethal saturation, ILOS; tested at 20°C). showed high capacity acclimation, linearly increasing acclimation temperature (slope = 0.55, adjusted R2 0.79), an overall response ratio (ARR) 0.58, from 14°C (CTmax 29.4 ± 0.2°C, mean S.E.M.) 22°C 34.1 0.2°C). Acute most negatively impacted in 14°C-acclimated fish (ILOS 15.79 0.74% air saturation), but 20°C conferred greatest 2.60 1.74% saturation). Interestingly, individuals that had been previously lower than naïve no testing. This was particularly apparent hypoxia-tolerant 20°C-acclimated fish, whereas persisted entire 15-h duration trial did not lose equilibrium saturation levels below 20%. Warm-acclimated demonstrated significantly smaller relative ventricular mass, indicating potential changes tissue delivery, other red blood cell characteristics somatic indices. These data suggest are resilient hypoxia, order which these experienced exposures acute or chronic have important effects on phenotype.

Language: Английский

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Narrow Margins: Aerobic Performance and Temperature Tolerance of Coral Reef Fishes Facing Extreme Thermal Variability

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(3)

Published: March 1, 2025

Climate change is driving rising average sea temperatures and the intensification of thermal variability. Tropical coral reef fishes have evolved under thermally stable conditions to function optimally within a narrow temperature range, with many currently living close their upper limits. However, recent work has demonstrated that some species possess additional capacity, such as reductions in basal metabolic rates (i.e., 'plastic floors'), compensate for acute effects challenges when assessed over multigenerational timeframes. In this study, we use floors concrete ceilings' hypothesis generate then test predictions regarding physiology world's hottest most variable ecosystem (southern Arabian/Persian Gulf). By comparing three (Scolopsis ghanam, Ecsenius pulcher Cheilodipterus novemstriatus) from southern Gulf, an annual range 18.0°C-36.5°C, conspecifics nearby but more benign (~21.0°C-32.0°C) reefs Gulf Oman, find enhanced limits broadening performance curves aerobic scope no evidence changes ('plastic floors'). Despite these conserved increases tolerance, summer safety margins were 1.47°C lower than those demonstrating while tolerance tropical somewhat plastic timeframes, its rate likely insufficient keep pace growing variability expected climate change.

Language: Английский

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Implications of chronic hypoxia during development in red drum

Journal of Experimental Biology, Journal Year: 2024, Volume and Issue: 227(16)

Published: Aug. 15, 2024

ABSTRACT Respiratory plasticity is a beneficial response to chronic hypoxia in fish. Red drum, teleost that commonly experiences the Gulf of Mexico, have shown respiratory following sublethal exposure as juveniles, but implications during development are unknown. We exposed red drum embryos (40% air saturation) or normoxia (100% for 3 days post fertilization (dpf). This time frame encompasses hatch and exogenous feeding. At dpf, there was no difference survival changes size. After 3-day exposure, all larvae were moved reared common normoxic conditions. Fish ∼3 months effects developmental on swim performance whole-animal aerobic metabolism measured. used cross design wherein fish from (N=24) exercised tunnels both (40%, n=12) (100%, conditions, likewise hypoxia-exposed (n=10 each group). Oxygen consumption, critical speed (Ucrit), oxygen threshold (Pcrit) mitochondrial respiration Hypoxia-exposed had higher scope, maximum metabolic rate, liver efficiency relative control normoxia. Interestingly, showed increased sensitivity (higher Pcrit) recruited burst swimming at lower speeds These data provide evidence early leads complex later life.

Language: Английский

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Physiological responses of euryhaline marine fish to naturally-occurring hypersalinity

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology, Journal Year: 2024, Volume and Issue: unknown, P. 111768 - 111768

Published: Oct. 1, 2024

Language: Английский

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