Hypoxia threatens coral and sea anemone early life stages

Limnology and Oceanography, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 21, 2025

Abstract Seawater hypoxia is increasing globally and can drive declines in organismal performance across a wide range of marine taxa. However, the effects on early life stages (e.g., larvae juveniles) are largely unknown, it unclear how evolutionary histories may influence these outcomes. Here, we addressed this question by comparing responses three cnidarian species representing histories: reef‐building coral Galaxea fascicularis , broadcast spawner with horizontal transmission endosymbiotic algae (family Symbiodiniaceae); Porites astreoides brooder vertical endosymbiont transmission; estuarine sea anemone Nematostella vectensis non‐symbiotic spawner. Transient exposure to (dissolved oxygen < 2 mg L −1 for 6 h) led decreased larval swimming growth all species, which resulted impaired settlement corals. Coral‐specific also included swelling, depressed respiration rates, decreases symbiont densities function. These results indicate both immediate latent negative physiology coral–algal mutualisms specifically. In addition, G. P. were sensitized heat stress following exposure, suggesting that combinatorial nature climate stressors will lead declining sensitization was not observed N. exposed hypoxia, be more resilient combined stressors. Overall, emphasize importance reducing anthropogenic carbon emissions limit further ocean deoxygenation warming.

Language: Английский

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Hypoxia Disrupts Sex‐Specific Physiology and Gene Expression Leading to Decreased Fitness in the Estuarine Sea Anemone Nematostella vectensis

Molecular Ecology, Journal Year: 2025, Volume and Issue: unknown

Published: April 7, 2025

ABSTRACT Coastal seawater hypoxia is increasing in temperate estuaries under global climate change, yet it unknown how low oxygen conditions affect most estuarine species. We found that has increased since the 1990s an estuary hosting sea anemone Nematostella vectensis (Jacques Cousteau National Estuarine Research Reserve, New Jersey, USA). Adult N. bred from anemones collected this exposed to three consecutive nights of (dissolved = 0.5–1.5 mg L −1 for ~12 h night ) during gametogenesis displayed decreased aerobic respiration rates and biomass, indicating metabolic disruption. Physiological declines were correlated with changes expression genes related oxygen‐dependent processes, many which are targets hypoxia‐inducible factor 1α (HIF1α), demonstrating activity transcription first time early‐diverging metazoan. The upregulation involved unfolded protein response endoplasmic reticulum Golgi apparatus homeostasis suggested misfolded proteins contributed disrupted physiology. Notably, these responses more pronounced females, sex‐specific sensitivity was also observed reproductive outcomes, female but not male fecundity following exposure. However, sperm males had higher mitochondrial membrane potential, altered spermatogenesis. Further, crosses performed gametes hypoxia‐exposed adults yielded strikingly developmental success (~2%), larvae did develop similar accelerated settlement compared controls. Overall, depressed fitness by over 95%, suggesting even stress‐tolerant species may be threatened coastal deoxygenation.

Language: Английский

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“Bet hedging” against climate change in developing and adult animals: roles for stochastic gene expression, phenotypic plasticity, epigenetic inheritance and adaptation

Frontiers in Physiology, Journal Year: 2023, Volume and Issue: 14

Published: Oct. 6, 2023

Animals from embryos to adults experiencing stress climate change have numerous mechanisms available for enhancing their long-term survival. In this review we consider these options, and how viable they are in a world increasingly extreme weather associated with change. A deeply understood mechanism involves natural selection, leading evolution of new adaptations that help cope stochastic events While potentially effective at staving off environmental challenges, such typically occur very slowly incrementally over evolutionary time. Consequently, adaptation through selection is most instances regarded as too slow aid survival rapidly changing environments, especially when considering the nature Alternative operating much shorter time frame than involve rapid creation alternate phenotypes within life cycle or few generations. Stochastic gene expression creates multiple same genotype even absence cues. contrast, other phenotype externally driven by clues include well-understood developmental phenotypic plasticity (variation, flexibility), which can enable rapid, within-generation changes. Increasingly appreciated epigenetic influences during development changes also immediately be widespread throughout population, rather confined individuals case favorable mutations. Such epigenetically-induced arise response stressors generation across generations just “sunsetted” stressor dissipates, providing some capability withstand emerging Importantly, resulting not necessarily mutually exclusive, allowing classic “bet hedging”. Thus, appearance single population provides optimal future environment. This enhances Finally, end recommendations physiological experiments, recommending particular experiments investigating flexibility adopt more realistic protocols reflect weather.

Language: Английский

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Acute heat priming promotes short-term climate resilience of early life stages in a model sea anemone

PeerJ, Journal Year: 2023, Volume and Issue: 11, P. e16574 - e16574

Published: Dec. 5, 2023

Across diverse taxa, sublethal exposure to abiotic stressors early in life can lead benefits such as increased stress tolerance upon repeat exposure. This phenomenon, known hormetic priming, is largely unexplored stages of marine invertebrates, which are increasingly threatened by anthropogenic climate change. To investigate this larvae the sea anemone and model invertebrate Nematostella vectensis were exposed control (18 °C) or elevated (24 °C, 30 35 39 temperatures for 1 h at 3 days post-fertilization (DPF), followed return °C). The animals then assessed growth, development, metabolic rates, heat 4, 7, 11 DPF. Priming intermediately augmented growth development compared controls priming °C. Indeed, °C hampered developmental progression, with around 40% still planula stage DPF, contrast 0% all other groups. Total protein content, a proxy biomass, respiration rates not significantly affected suggesting resilience. Heat was quantified acute exposures, higher primed intermediate those time points. possible molecular mechanism observed changes tolerance, expression shock 70 (HSP70) Expression HSP70 increasing temperature, presence doublet band persistent negative effects on homeostasis. Interestingly, second cohort cultured 6 weeks continued display responses, whereas lost; contrast, short-term extreme (39 persisted. These results demonstrate that some dose-dependent waned over while others persisted, resulting heterogeneity organismal performance across ontogeny following priming. Overall, these findings suggest may augment resilience via modulation key physiological phenotypes, also affirming need limit further ocean warming.

Language: Английский

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Characterization of a sperm motility signalling pathway in a gonochoric coral suggests conservation across cnidarian sexual systems

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(2004)

Published: Aug. 2, 2023

Most stony corals liberate their gametes into the water column via broadcast spawning, where fertilization hinges upon activation of directional sperm motility. Sperm from gonochoric and hermaphroditic display distinct morphological molecular phenotypes, yet it is unknown whether signalling pathways controlling motility are also between these sexual systems. Here, we addressed this knowledge gap using gonochoric, spawning coral Astrangia poculata . We found that cytosolic alkalinization activates pH-sensing enzyme soluble adenylyl cyclase (sAC), which required for Additionally, demonstrate first time in any cnidarian sAC activity leads to protein kinase A (PKA) activation, PKA contributes activation. Ultrastructures A. displayed homology with other cnidarians, exhibited broad structural functional conservation across phylum. These results indicate a conserved role pH-dependent sAC-cAMP-PKA systems, suggest pathway may be ancestral metazoans. Finally, dynamics pH-sensitive play critical determining sensitivity marine invertebrate reproduction anthropogenic ocean acidification.

Language: Английский

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