Long-lived Species Research Articles

Analyzing the Life History of Caimans: The Growth Dynamics of Caiman latirostris From an Osteohistological Approach.

Skeletochronology and growth dynamics are intensively investigated in vertebrate osteohistology. These techniques are particularly important for interpreting the life history of long-lived species, such as crocodilians. To understand the longevity, growth dynamics, sexual maturity, and sexual dimorphism of caimans we studied an almost complete ontogenetic series of captive and wild specimens of Caiman latirostris from different localities of Argentina. We identified both cyclical and noncyclical growth marks in juvenile caimans, and we suggest that the latter are associated with environmental stress. By overlapping the growth marks of different individuals, we were able to estimate the minimum age of each specimen. Variations in growth rate are evident in different bones, with the femur and scapula having the highest growth rates, while the fibula and pubis have much slower growth rates. We were able to determine the approximate age of sexual maturity from growth curves deduced from osteohistology, which concurred with those assessed in ecological studies. Additionally based on the growth curves we were able to document different growth dynamics which may be related to sexual dimorphism. This study provides valuable insights into the life history and ecological dynamics of crocodilians, shedding light on their growth patterns, attainment of sexual maturity, and the influence of environmental factors on growth. Furthermore it documents the intraspecific and interelemental osteohistological variation in crocodilians and has direct implications for studies that assess the life history of extinct archosaurs and other sauropsids.

How Important Is Informed Natal Dispersal for Modelling the Demographic and Genetic Effects of Environmental Variability?

Dispersal is a fundamental ecological process that influences population dynamics and genetic diversity and is therefore an important component of the models used to simulate population responses to environmental change. We considered informed dispersal in relation to settlement location, where individuals could optimise selection of settlement location with regard to per capita resource availability and investigated the importance of this type of informed dispersal for simulated demography and genetic diversity under different biological and environmental scenarios. We used an individual-based simulation model scaled with reference to the ecology of small mammals in fire prone savanna ecosystems. We simulated demographic and genetic processes under informed and uninformed dispersal across several scenarios of life history, environmental heterogeneity (patch size and patch dynamics) and dispersal distance. The effect of the dispersal method on population size far outweighed that of dispersal distance under all combinations of habitat quality, temporal dynamics, patch size and dispersal distance modelled. The effects of habitat patch size and habitat dynamics (representing temporal change in habitat quality such as that potentially generated by disturbance) were low under most of the scenarios modelled. Informed dispersal influenced genetic diversity and differentiation, but the effects were weaker than those of dispersal distance. The genetic effect of informed dispersal occurred through the effect on genetic diversity of the overall metapopulation, while the dispersal distance influenced gene flow and genetic diversity within subpopulations. Informed dispersal was less effective in increasing population size in models of a long-lived species with overlapping generations. This was particularly true when habitat quality was dynamic and natal dispersal choices did not result in lifelong habitat quality outcomes. Our results suggest that including informed decision-making in dispersal in simulation models leads to different projections of demography, genetic diversity and susceptibility to environmental change.

Insights on bacteria inactivation in water by cold plasma: Effect of water matrix and pulsed plasmas waveform on physicochemical water properties, species formation and inactivation efficiency of Escherichia coli

This study investigates the inactivation of Escherichia coli (E. coli) using pulsed dielectric barrier discharges (DBDs) powered by high-voltage nanosecond and/or microsecond pulses to establish optimal operational conditions. The effects of pulse voltage waveform and water matrix (distilled vs. tap water) were evaluated in terms of inactivation efficiency and energy consumption, along with the generation of reactive oxygen and nitrogen species (RONS). Complete E. coli inactivation (9-log CFU/ml) in distilled water was achieved within 20 min of nanopulsed-DBD treatment, coinciding with rapid acidification, while in tap water, 90 min was required for complete inactivation. Interestingly, at treatment times with similar pH levels between water types, E. coli inactivation was more effective in tap water. Ozone concentrations showed the most significant difference, being ∼6 times higher in distilled water (10.3 mg/L) than in tap water (1.7 mg/L). Although distilled and tap water had similar concentrations of short- and long-lived plasma species, the differing inactivation efficiencies indicate a synergistic effect between pH reduction and reactive species in impairing E. coli functionality. Micropulsed-DBD led to increased concentration of plasma species, faster acidification and inactivation in tap water (complete inactivation within 8 min), but at significantly higher electrical energy per order (56.9 kWh/m3 compared to 17.4 kWh/m3 for nanopulsed-DBD). The lowest energy per order was recorded for nanopulsed-DBD in distilled water, at 3.8 kWh/m³, highlighting pulsed-DBD plasma as a safe and energy-efficient method for water disinfection. This study offers valuable insights into using an innovative, sustainable plasma-based approach for bacterial inactivation.

Telomere Dynamics in Human Health and Disease.

Telomere function is critical for genomic stability; in the context of a functional TP53 response, telomere erosion leads to a G1/S cell-cycle arrest and the induction of replicative senescence, a process that is considered to underpin the ageing process in long-lived species. Abrogation of the TP53 pathway allows for continued cell division, telomere erosion, and the complete loss of telomere function; the ensuing genomic instability facilitates clonal evolution and malignant progression. Telomeres display extensive length heterogeneity in the population that is established at birth, and this affects the individual risk of a broad range of diseases, including cardiovascular disease and cancer. In this perspective, I discuss telomere length heterogeneity at the levels of the population, individual, and cell, and consider how the dynamics of these essential chromosomal structures contribute to human disease.

The Premature Mortality of Sabinos or Montezuma Bald Cypress (Taxodium mucronatum Ten.) in the State of Durango, Mexico

The juniper (Taxodium mucronatum Ten. of the Cupressaceae family) is a long-lived species that forms gallery forests. Dozens of dead junipers > 100 years old have been identified in the San Pedro Mezquital watershed in Durango, Mexico. This work determines the causes of death of these specimens. The work was carried out in the field and in the laboratory, where in the former the surface of the damaged trees was identified, together with the changes observed in the watercourses. In the latter, sabino seedlings were transported to the work center and exposed for 7 days in containers with gravel to five types of wastewater generated in the region. With the above, the conditions experienced by the adult trees in the field were studied, as well as the sensitivity of the young specimens to the types of water quality, and the differences were validated with ANOVA tests. Five sites with dead junipers were found, ranging in size from 0.5 to 4 ha, with ages between 200 and 400 years. It was found that during the dry season, water is diverted to irrigated areas, leaving some areas without water for several months. The shoots survived in most of the water qualities, except the one with high salinity (3.34 mS/cm). It is concluded that the lack of water in the rivers had a stronger influence than the water quality and is the probable cause of the death of the sabino.

Oxidative Stress in an African Ground Squirrel, a Case of Healthy Aging and Reproduction.

Oxidative stress plays a crucial role in mediating life-history processes, where it can compromise survival and reproduction through harmful alterations to DNA, lipids, and proteins. In this study, we investigated oxidative stress in Cape ground squirrels (Xerus inauris), a longer-lived African ground squirrel species with a high reproductive skew and unique life history strategies. We measured oxidative stress as total antioxidant capacity (TAC), total oxidant status (TOS), and an oxidative stress index (OSI) in blood plasma from individuals of approximately known ages. Our results reveal a distinct pattern of decreasing oxidative stress with age, consistent across both sexes. Females exhibited lower OSI and TOS levels than males. Males employing different life-history strategies, namely natal (staying at home), had significantly lower oxidative stress compared to the band (roaming male groups), likely due to variations in metabolic rate, activity, and feeding rates. However, both strategies exhibited reduced oxidative stress with age, though the underlying mechanisms require further investigation. We propose that selection pressures favoring survival contributed to the observed reduction in oxidative stress with age, potentially maximizing lifetime reproductive success in this species.

Exploring the influences of resource limitation and plant aging on pollen development in Azorella nivalis Phil. (Apiaceae), a long-lived high-Andean cushion plant.

Angiosperm pollen, the male gametophyte, plays a crucial role in facilitating fertilization by protecting and transporting male sperm cells to the female pistil. Despite their seemingly simple structure, pollen grains undergo intricate development to produce viable sperm cells capable of fertilizing the egg cell. Factors such as resource limitation and plant aging can disrupt normal pollen development and affect pollen performance. We investigated the influence of plant resources and aging on pollen developmental failure in Azorella nivalis Phil., an exceptionally long-lived high-Andean species that grows in a stressful alpine environment. Leveraging the modular nature of plants, we aimed to identify intra-individual sources of variation in pollen developmental failure. By using pollen viability and variation in viable pollen grain size as indicators of pollen developmental performance, we assessed whether proxies of plant resource availability and aging influenced these pollen traits at the inter-individual, inter-flower and intra-flower levels. Our findings revealed decreased pollen viability in putative resource-depleted flowers and in shoots that experienced higher levels of meristematic divisions from the zygote (i.e., greater cell depth). Additionally, we observed increased variability in the size of viable pollen grains in resource-depleted anthers. Our study suggests that resource availability and shoot aging are critical determinants shaping pollen development in long-lived plants at the intra-individual level. These findings contribute to our understanding of how differences in male fitness can arise in plants, with implications for their evolutionary trajectory.

Forever chemicals don't make hero mutant ninja turtles: Elevated PFAS levels linked to unusual scute development in newly emerged freshwater turtle hatchlings (Emydura macquarii macquarii) and a reduction in turtle populations

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants known to pose significant risks to human and wildlife health. Freshwater turtles (Emydura macquarii macquarii), as long-lived species inhabiting aquatic ecosystems, are particularly vulnerable to PFAS bioaccumulation. This study investigated the multifaceted impact of PFAS contamination on these turtles, focusing on metabolic disruptions, reproductive success, hatchling health, and population impacts. Comprehensive analyses, including proteomics, lipidomics, metabolomics, and histopathology, were conducted on turtles from PFAS-impacted, control, and reference sites. The findings reveal significant metabolic disruptions in PFAS-exposed turtles, with alterations in amino acid and lipid metabolism, energy production, and oxidative stress responses. Proteomic analysis identified several health biomarkers indicative of early disease progression. Despite high levels of PFAS in tissues and organs, no gross or histopathological phenotypical abnormalities were directly linked to PFAS exposure. Gravid females from contaminated sites exhibited altered egg composition, particularly in magnesium to calcium ratios, potentially affecting eggshell strength. Biochemical profiles of egg albumin and yolk indicated significant differences in metabolites and lipids between contaminated and reference sites, suggesting potential impacts on embryo development. Hatchling deformities were notably higher and with increased frequency in terms of the types of deformities at the PFAS-impacted sites, with common defects including abnormal intergular scale shapes and marginal scale counts. Furthermore, the demographic profile of the turtle population showed a lack of juvenile turtles at contaminated sites, indicating reduced recruitment and potential long-term population declines. This indicates a field-based demonstration of an Adverse Outcome Pathway, from elevated levels of PFAS in the turtles, to biochemical perturbations within the animals, and finally population effects. These findings underscore the urgent need for regulatory measures to address PFAS contamination and its detrimental effects on wildlife.

Metal and arsenic contamination of a terrestrial top-predator, the black kite (Milvus migrans), after the Aznalcóllar mine spill (southwestern Spain): Temporal trends and fitness consequences

Top-predators serve as sentinels of ecosystem health due to their sensitivity to environmental contamination. However, our understanding on how contaminants affect individual fitness is still scarce, especially for long-lived species. Here, we measured blood concentrations of 4 metals (Cd, Cu, Pb, and Zn) and one metalloid (As) in black kite (Milvus migrans) adults from Doñana National Park (SW Spain) following a major mine spill. Besides temporal variation (1998–2001) in metal and As concentrations, we tested how metal and As profiles changed across individuals in relation to their sex, age or breeding status, and examined whether metal and As concentrations affected individuals' fitness (breeding success and mortality). We found that, overall, blood concentrations of Pb, Cd and As increased throughout the study period in black kites, mirroring the progressive increase previously reported for their main prey. Both sex (Cu and Zn) and breeding status (Zn and Pb) affected element concentrations. Non-breeding (floater) females had higher levels of Zn than their breeding counterparts. The same pattern of higher contamination in floaters was observed for Pb, which might be related to differences in diet and foraging activity between breeders and floaters. The percentage of the individuals with Pb concentrations that exceeded toxicity thresholds (> 200 μg/L) was relatively high (15.4 %). Moreover, Pb concentrations were negatively correlated to males' breeding success. We found no clear evidence to support metal and As effects on survival or life expectancy after accounting for environmental and individual sources of variation. Our results highlight the importance of long-term studies of marked individuals in wild populations; detailed knowledge of ecological processes relevant to these populations, combined with measures of contaminant exposure at individual level, provides opportunities to enhance our understanding of its fitness effects and potential demographic consequences.

The microbiome of the main deep-water scleractinian reef-framework engineers from the Southwestern Atlantic

Deep waters (>150 m) shelter half of the extant diversity of scleractinian corals, including framework reef-forming species. However, to date, the relationship between microorganisms and corals has focused mainly on their zooxanthellate shallow-water counterparts. Here, using 16S rRNA gene amplicon sequencing, we explore the microbiome of all major Atlantic deep-water scleractinian reef framework engineers (Desmophyllum pertusum, Solenosmilia variabilis, Madrepora oculata, and Enallopsammia rostrata), and correlated them with environmental characteristics. Colony fragments of each coral species used in the present study were sampled from three sedimentary basins off the Southeastern coast of Brazil, including two water masses (Antarctic Intermediate Water and South Atlantic Coastal Water). Although representing distant scleractinian evolutionarily lineages, some evolving apart for more than 300Ma, our results suggest a taxonomic homogeneity in their microbial profile. The species-specific microbial core, as well as the core common to all examined species, were identified. Such cores are composed of bacterial genera that have already been observed in other coral species, including those from zooxanthellate species. Such a pattern suggests an active selection of the microbial community by their hosts, a phenomenon that seems to be fundamental for holobiont fitness, especially in long-lived species, such as corals. Besides the microbial core, for all examined species, part of the determined microbiome was flexible and responded to environmental drivers. This flexibility is most probably related to the host's ability to adapt in ecological time scales. Taken together, these holobiont abilities may be crucial to its success in both ecological and geological timescales.

Beyond Peto's Paradox: Expanding the Study of Cancer Resistance Across Species.

Peto's paradox, which highlights the lower-than-expected cancer rates in larger and/or longer-lived species, is a cornerstone of discussions at the intersection of ecology, evolution, and cancer research. It prompts investigations into how species with traits that theoretically increase cancer risk manage to exhibit cancer resistance, with the ultimate goal of uncovering novel therapies for humans. Building on these foundational insights, we propose expanding the research focus to species that, despite possessing traits beyond size and longevity that theoretically increase their cancer risk, exhibit unexpected cancer resistance. Testing Peto's paradox without interference from transient dynamics also requires considering species that are at an equilibrium between cancer risks and defenses, which is increasingly challenging due to anthropogenic activities. Additionally, we argue that transmissible cancers could significantly help in understanding how the metastatic process might be naturally suppressed. This research perspective is timely and aims to support the continued and in-depth identification of anti-cancer adaptations retained throughout evolution in the animal kingdom.

Effects of pulse rise time and pulse width on discharge mode transition of SDBD plasma under repetitive pulses

Abstract Affected by environmental states and power supply parameters, the discharge mode of surface dielectric barrier discharge (SDBD) plasma may gradually transfer from O3 mode to NO x mode, resulting in various gas-phase species for different applications. Despite the intensive study of attempts to control this discharge mode transition by changing discharge conditions and power excitations in recent years, the effects of the pulse rise time and the pulse width on the discharge mode transition have not been discussed. In the present study, a SDBD was excited by repetitive pulses with different pulse rise times or pulse widths, and the time-varying concentrations of key long-lived species (O3 and NO2) were quantified. The results demonstrated that it was possible to modulate the discharge mode by adjusting pulse rise time/pulse width. The quenching of O3 was observed to occur at a faster rate and the mode transition was noted to occur at an earlier point in time as the pulse rise time decreased from 225 ns to 125 ns and the pulse width increased from 0.5 μs to 4 μs. The employment of a zero-dimensional model for the analysis of plasma chemical kinetics revealed that the reduction in pulse rise time and the prolongation of pulse width resulted in an increase in the mean vibrational energy of N2(v) and a more rapid electrode temperature rise caused by plasma heating. The former enhanced the generation of NO, while the latter accelerated the thermal decomposition of O3, thereby promoting the speed of mode transition.

Apparent survival and population turnover in a long-lived generalist raptor: a comparison of estimation methods

Adult survival and turnover rates are often estimated in long-lived species as the primary drivers of population dynamics. Various methods have been used, yet comparison of estimation methods is seldom undertaken. To address this gap, we used colour-ringing across different age groups, as well as GPS-tracking and genetic analysis of shed feathers, to estimate these critical parameters in a population of the medium-sized bird of prey, the Lesser Spotted Eagle. According to the colour-ringing data, the apparent survival during the first year of life (0.21) was more than four times lower than that of birds older than one year (0.88); the GPS-tracking (0.84) and genetic analysis (0.81) yielded similar survival estimates. All used techniques indicated a stable trend in apparent survival rates. However, population turnover rates derived from genetic feather analysis (0.17–0.43) exceeded expectations based on apparent survival estimates, as well as those derived from colour-rings (0.05–0.17) and GPS-tracking (0.05–0.08). Notably, all markers indicated high site fidelity among adult eagles, with breeding dispersal events being infrequent. Our findings underscore the utility of diverse methods for estimating apparent survival, though the ecological characteristics of the species may influence the efficacy of each method. However, estimates of population turnover rates were notably influenced by the choice of method and should be interpreted cautiously before recommending management actions.

The Cost of Self-Defense: Browsing Effects in the Rare Plant Species Salix arizonica.

Coevolution between plants and their animal predators has led to diverse defensive adaptations. Multiple theories of defense propose that there are resource allocation costs associated with producing chemical defenses. One leading hypothesis, optimal defense theory (ODT), suggests that natural selection will result in the allocation of resources to defenses that optimize the cost-to-benefit ratio between defense and other functional processes. The population decline of the rare subalpine wetland species, Arizona willow (Salix arizonica), has been attributed to various biotic and abiotic factors, with browsing from wild and domestic ungulates as a significant concern for at least three decades. In a field experiment using natural populations, we compare the relationship between phytochemical defense and height in Arizona willows with and without long-term protection from browsing via browse exclosures. Consistent with the predictions of ODT, individuals with physical protection from ungulate browsing for multiple years had significantly lower phenolic glycoside (PG) concentrations and increased plant height compared to unprotected individuals. A similar pattern was found across all individuals, whereby total PG concentration and height were negatively correlated. In a short-term experiment in natural populations, changes in levels of defense were not observed when plants received protection for only one growing season. The contrasting pattern of defense plasticity in response to long-term versus short-term physical protection suggests a differential plastic response in this long-lived species. Delayed reduction in PG concentration may serve as a benefit to avoid mismatches between environmental cues and responses. Our research sheds light on the intricate dynamics between plant-defense strategies, environmental pressures, and evolutionary adaptations in shaping plant-browser interactions.

Early and adult life environmental effects on reproductive performance in preindustrial women.

Early life environments can have long-lasting effects on adult reproductive performance, but disentangling the influence of early and adult life environments on fitness is challenging, especially for long-lived species. Using a detailed dataset spanning over two centuries, we studied how both early and adult life environments impacted reproductive performance in preindustrial women. Due to a wide geographic range, agricultural production was lower in northern compared to southern parishes, and health conditions were worse in urban than rural parishes. We tested whether reproductive traits and offspring survival varied between early and adult life environments by comparing women who moved between different environments during their lifetime with those who moved parishes but remained in the same environment. Our findings reveal that urban-born women had an earlier age at first reproduction and less offspring surviving to adulthood than rural-born women. Moreover, switching from urban to rural led to increased offspring survival, while switching from rural to urban had the opposite effect. Finally, women who switched from rural to urban and from South to North had their first child at an older age compared to those who stayed in the same environment type. Our study underscores the complex and interactive effects of early and adult life environments on reproductive traits, highlighting the need to consider both when studying environmental effects on reproductive outcomes.

Early life adversity has sex-dependent effects on survival across the lifespan in rhesus macaques.

Exposure to early life adversity is linked to detrimental fitness outcomes across taxa. Owing to the challenges of collecting longitudinal data, direct evidence for long-term fitness effects of early life adversity from long-lived species remains relatively scarce. Here, we test the effects of early life adversity on male and female longevity in a free-ranging population of rhesus macaques (Macaca mulatta) on Cayo Santiago, Puerto Rico. We leveraged six decades of data to quantify the relative importance of 10 forms of early life adversity for 6599 macaques. Individuals that experienced more early life adversity died earlier than those that experienced less adversity. Mortality risk was highest during early life, defined as birth to 4 years old, but heightened mortality risk was also present in macaques that survived to adulthood. Females and males were affected differently by some forms of adversity, and these differences might be driven by varying energetic demands and dispersal patterns. Our results show that the fitness consequences of early life adversity are not uniform across individuals but vary as a function of the type of adversity, timing and social context, and thus contribute to our limited but growing understanding of the evolution of early life sensitivities.This article is part of the discussion meeting issue 'Understanding age and society using natural populations'.

Post-senescence reproductive rebound in Daphnia associated with reversal of age-related transcriptional changes.

A long-lived species of zooplankton microcrustaceans, Daphnia magna, sometimes exhibits late-life rebound of reproduction, briefly reversing reproductive senescence. Such events are often interpreted as terminal investments in anticipation of imminent mortality. We demonstrate that such post-senescence reproductive events (PSREs) neither cause nor anticipate increased mortality. We analyze an RNAseq experiment comparing young, old reproductively senescent, and old PSRE Daphnia females. We first show that overall age-related transcriptional changes are dominated by the increased transcription of guanidine monophosphate synthases and guanylate cyclases, as well as two groups of presumed transposon-encoded proteins, and by a drop in transcription of protein synthesis-related genes. We then focus on gene families and functional groups in which full or partial reversal of age-related transcriptional changes occur. This analysis reveals a reversal, in the PSRE individuals, of age-related up-regulation of apolipoproteins D, lysosomal lipases, and peptidases as well as several proteins related to mitochondrial and muscle functions. While it is not certain which of these changes enable reproductive rejuvenation, and which are by-products of processes that lead to it, we present some evidence that post-senescence reproductive events are associated with the reversal of age-related protein and lipid aggregates removal and apoptosis.

Biodiversity associated with a coralligenous build-up off Sicily (Ionian Sea)

Coralligenous is one of the most important habitats of the Mediterranean Sea hosting a very high biodiversity that, however, has not been fully investigated yet. The paper addressed the study of the biodiversity of a coralligenous bioconstruction collected at a depth of 36.7 m off Marzamemi (SE Sicily, Ionian Sea). The species diversity, composition and structure of the main associated taxonomic groups were investigated in order to identify possible differences between the communities of the hard framework (mainly built by calcified corallinales) and the canopy cover. The examined build-up showed significant species diversity for almost all groups. Bryozoans were the most diversified group and, together with foraminifers, also the most abundant both on the canopy and the frame. Further groups showed high species diversity (except for serpulids) and total abundance (except for molluscs) on the canopy rather than on the frame. Due to their different nature and microenvironmental parameters, the canopy and the frame hosted different communities. Besides juvenile specimens, the canopy mostly hosted unmineralized and weakly mineralized, small-sized, short-lived species well adapted to living on ephemeral and flexible substrates. On the contrary, the rigid and persistent frame mostly hosted highly mineralized, large, long-lived species, which usually contributed to the building and strengthening of the bioconstruction. Unlike mapping and monitoring, a thorough description of coralligenous biodiversity requires accurate naked eye and microscopical analysis assisted by SEM investigation due to the small size and cryptic behaviour of several species.

Climate change drives fish communities: Changing multiple facets of fish biodiversity in the Northwest Pacific Ocean

Global marine biodiversity is experiencing significant alterations due to climate change. Incorporating phylogenetic and functional diversity may provide novel insights into these impacts. This study used an ensemble model approach (random forest and boosted regression tree), to predict the habitat distribution of 47 fish species in the Northwestern Pacific under contemporary (2000–2014) and future scenarios (2040–2050, 2090–2100). We first examined the relationship between eleven functional traits and habitat changes, predicting the spatial distribution of functional traits within fish communities. A significant correlation was observed between temperature preference and habitat changes, highlighting the vulnerability of cold-water species and potential advantages for warm-water species in the future. Moreover, fish communities exhibited a spatial gradient distribution with southern regions characterized by shorter-lived and earlier maturity, contrasting with longer-lived and later maturity species in the north. Secondly, to assess the impact of climate change on marine biodiversity, we explored the taxonomic, phylogenetic, and functional diversity under contemporary and future scenarios, revealing higher indices in the East China Sea (ECS) and the coastal sea of Japan, with the Taiwan Strait emerging as a contemporary biodiversity hotspot. In future scenarios, the three biodiversity indices would decline in the Yellow Sea and ECS, but increase in the sea beyond the continental shelf, coastal sea of Hokkaido, and Sea of Okhotsk. Lastly, we explored processes and mechanisms in the change of community composition. By quantifying β-diversity, we identified species loss (nestedness) as the primary driver of fish community change by 2040–2050, with species replacement (turnover) predicted to become dominant in the far future. Our results explore the potential changes in multiple facets of fish biodiversity, providing crucial insights for policymakers aiming to protect fish resources and biodiversity.

An immune challenge induces a decline in parental effort and compensation by the mate.

Immune defense is fundamental to diminish the negative effects of the attack of infectious agents, yet the activation of the immune system entails costs and may compromise other life-history traits such as reproduction. In reproductive brown booby pairs (Sula leucogaster), we experimentally imposed an immune challenge during incubation, by intraperitoneally injecting Escherichia coli lipopolysaccharide (LPS), in either the male or the female. We aimed to test whether activation of the immune response results in (1) an increase in oxidative stress parameters, (2) a decline in post-hatching parental care in the treated individual, and (3) a compensation of the post-hatching parental effort by the nontreated mate. We found that activation of the immune response during incubation did not increase oxidative damage to lipids or total antioxidant capacity. However, mounting an immune response compromised parental effort during the chick-rearing period: compared to controls, LPS-treated parents showed roughly a 50% decline in the rate of preening and offspring feeding in response to begging. Interestingly, mates of LPS-treated parents increased their feeding rate suggesting parental care compensation. According to a scenario of full compensation, the decline in parental effort of LPS-treated parents did not result in poorer offspring growth or immune response, or increased levels of oxidative stress parameters. These findings suggest that in a long-lived species with long-lasting biparental care, an immune challenge compromises parental care, favoring parental compensation as a strategy to mitigate costs in terms of offspring success.