Offspring Size Research Articles

Timing and Intensity of Weather Events Shape Nestling Development Strategies in Three Alpine Breeding Songbirds

Across taxa, offspring size traits are linked to survival and life-time fitness. Inclement weather can be a major constraint on offspring growth and parental care. Despite the adaptive benefits of larger offspring, we have a limited understanding of the effects of severe environmental conditions across developmental stages and how coping strategies differ among species. We assessed the influence of inclement weather on offspring size and mass traits within populations of three alpine breeding songbirds in British Columbia: 1) horned lark (Eremophila alpestris), 2) dark-eyed junco (Junco hyemalis), and 3) savannah sparrow (Passerculus sandwichensis). Specifically, we investigated at which stages during early-life development offspring are most vulnerable to inclement weather and whether thresholds exist in the developmental response to severe weather events. Across species, we identified two critical periods that best predicted offspring size: 1) clutch initiation, and 2) the nestling stage. Colder temperatures experienced by the female during clutch initiation were associated with larger, heavier offspring in horned larks but smaller offspring for savannah sparrows, indicating the potential for maternal effects, albeit acting through different mechanisms. Additionally, horned lark offspring were resilient to colder average temperatures during the nestling stage but were vulnerable to extreme cold events and multi-day storms. In contrast, dark-eyed junco nestlings were robust to storms, but smaller size and mass traits were associated with lower daily maximum temperatures (i.e., more mild temperature challenges). We suggest species differences may be linked to life-history traits, such as: 1) the thermoregulatory benefits of larger body mass in horned larks, 2) the benefits of greater nest cover to buffer dark-eyed junco against precipitation events, and 3) delayed clutch initiation for savannah sparrows to limit exposure to cold storms. We provide evidence for stage-specific impacts of inclement weather on offspring development with implications for reproductive success. These results advance our understanding of early-life resilience to stochastic environments, as we may be able to predict differences in the vulnerability of alpine species to increasingly variable and severe weather conditions.

The allocation between egg size and clutch size depends on local nest survival rate in a mean of bet-hedging in a shorebird

BackgroundThe allocation of resources between offspring size and number is a central question of life-history theory. Although several studies have tested the existence of this trade-off, few studies have investigated how environmental variation influences the allocation of resources to offspring size and offspring number. Additionally, the relationship between population dynamics and the offspring size and number allocation is far less understood.MethodsWe investigate whether resource allocation between egg size and clutch size is influenced by the ambient temperature and whether it may be related to apparent nest survival rate. We measured 1548 eggs from 541 nests of two closely related shorebird species, the Kentish Plover (Charadrius alexandrinus) and the White-faced Plover (C. dealbatus) in China, in four populations that exhibit contrasting ambient environments. We weighed females, monitored nest survival, and calculated the variance of ambient temperature.ResultsAlthough we found that egg size and clutch size were all different between the four breeding populations, the reproductive investment (i.e. total clutch volume) was similar between populations. We also found that populations with a high survival rate had relatively larger eggs and a smaller clutch than populations with a low nest survival rate. The latter result is in line with a conservative/diversified bet-hedging strategy.ConclusionsOur findings suggest that plovers may increasing fitness by investing fewer, larger or many, small according local nest survival rate to make a similar investment in reproduction, and thereby may have an impact on population demography.

Context dependence of transgenerational plasticity: the influence of parental temperature depends on offspring environment and sex.

Under environmental change, the relationship between phenotype and fitness can change rapidly, leaving populations vulnerable. Plasticity within and between generations could provide the fastest mitigation to environmental change. However, plasticity may depend on interactions among parental environment, offspring environment and offspring sex, and we know little of how these interactions manifest. We examine the importance of parental and offspring thermal environment in the context of a terrestrial ectotherm (the jacky lizard, Amphibolurus muricatus), where the thermal environment depends on complex thermoregulatory behaviours. By manipulating both parental and offspring thermoregulatory (basking) opportunities in a full factorial design, we found that transgenerational plasticity was highly context dependent. Overall, longer parental thermoregulatory opportunities led to increased growth in offspring, providing a clear fitness benefit to daughters but inducing a cost of increased oxidative stress in sons. Daughters, but not sons, received the greatest advantage when their thermal environment matched that of their parents. The offspring thermal environment had little independent effect on offspring phenotype. Together, the results suggest that both directional selection on offspring size (leading to growth being dependent on thermal conditions) and selection for anticipatory parental effects operate, but with a different balance in males and females. More broadly, restrictions in thermoregulatory opportunities under climatic warming will have negative consequences both within and between generations, but the exact nature will depend on the evolved functional form of plasticity.

Adaptive significance of light and food for a kleptoplastic sea slug: implications for photosynthesis.

Sacoglossan sea slugs can 'steal' chloroplasts from their algal food and use them for photosynthesis (kleptoplasty). Although it has been shown that light has positive effects on survival and body size retention of some sacoglossans likely through photosynthesis, it is unknown whether light affects their fitness components such as number of offspring or offspring size. Moreover, whether the effects of light extend over the sacoglossans' lifetime has been unexplored. To assess such long-term effects of light intensity and food availability on fitness components, we conducted a 15.9-week laboratory experiment using Elysia atroviridis under a combination of two light intensities (low or high) and two food conditions (with or without food). The total number of eggs laid was greater in the presence of both strong light and food than in other conditions, suggesting positive effects of both light intensity and food availability. The shell height at hatch was also largest in the presence of strong light and food. Larval rearing experiments showed that the size difference at hatch between conditions corresponded to a 1.19-1.93days growth and 7.9-18.1% survival increase. Thus, positive effects of light and food on the fitness components extend over the lifetime of E. atroviridis.

Previous exposure mediates the response of eelgrass to future warming via clonal transgenerational plasticity.

Mortality and shifts in species distributions are among the most obvious consequences of extreme climatic events. However, the sublethal effects of an extreme event can have persistent impacts throughout an individual's lifetime and into future generations via within-generation and transgenerational phenotypic plasticity. These changes can either confer resilience or increase susceptibility to subsequent stressful events, with impacts on population, community, and potentially ecosystem processes. Here, we show how a simulated extreme warming event causes persistent changes in the morphology and growth of a foundation species (eelgrass, Zostera marina) across multiple clonal generations and multiple years. The effect of previous parental exposure to warming increased aboveground biomass, shoot length, and aboveground-belowground biomass ratios while also greatly decreasing leaf growth rates. Long-term increases in aboveground-belowground biomass ratios could indicate an adaptive clonal transgenerational response to warmer climates that reduces the burden of increased respiration in belowground biomass. These transgenerational responses were likely decoupled from clonal parent provisioning as rhizome size of clonal offspring was standardized at planting and rhizome starch reserves were not impacted by warming treatments. Future investigations into potential epigenetic mechanisms underpinning such clonal transgenerational plasticity will be necessary to understand the resilience of asexual foundation species to repeated extreme climatic events.

Lizard Embryos Prioritize Posthatching Energy Reserves over Increased Hatchling Body Size during Development

Embryonic development in oviparous organisms is fueled by maternally allocated yolk, and many organisms hatch before that energy store is used completely; the resultant leftover (residual) yolk is internalized and may support early posthatching life. However, embryos that use most, or all, of their yolk supply before hatching should hatch at a larger size than those that do not exhaust those energy reserves, which could also have benefits for posthatching growth and survival. To examine the trade-off between residual yolk and offspring size, we experimentally reduced yolk quantity at oviposition in lizard eggs (Amphibolurus muricatus) and then quantified offspring size and the amount of internalized residual yolk. This design enabled us to determine whether embryos (1) exhaust yolk supply during development (thereby maximizing neonatal size) or (2) reduce neonatal size by retaining yolk reserves at hatching. Our data support the latter scenario. Eggs from the yolk-reduced treatment produced smaller offspring with a proportion of residual yolk similar to that of offspring from unmanipulated eggs, suggesting that the fitness benefits of posthatching energy stores outweigh those of larger neonatal size.

A maternal effect influences sensitivity to chlorpyrifos pesticide in the pest moth Spodoptera littoralis

Transgenerational effects on sensitivity to pesticides are poorly studied. This study investigated the transgenerational influences of maternal body mass in the major pest moth Spodoptera littoralis, with a focus on sensitivity to chlorpyrifos pesticide. In 147 clutches of a laboratory strain of S. littoralis, we compared larval mortality between control larvae and larvae treated with chlorpyrifos. Because of the classic positive relationships between offspring size and maternal size and between offspring size and offspring quality, sensitivity to chlorpyrifos was predicted to be lower in larvae of larger mothers. Surprisingly, we found the opposite result, with higher pesticide toxicity in larvae of larger mothers. This result is partly explained by the lack of a relationship between larval mass and larval sensitivity to chlorpyrifos. This means that another offspring characteristic linked to maternal size should have affected larval sensitivity to chlorpyrifos. More generally, knowledge of the effects of the traits and ecological environments of mothers on offspring sensitivity to pesticides remains limited. Ecotoxicologists should pay more attention to such maternal effects on sensitivity to pesticides, both in pests and non-target species.

Predicting egg size across temperatures in marine teleost fishes

AbstractMarine teleost fish species in colder environments generally produce larger eggs than those in warmer environments. This pattern is thought to reflect changes in the optimal strategy of allocation to offspring size and number across temperatures, yet quantitative assessments of this hypothesis are lacking. Here, we model optimal offspring size across temperatures in marine teleost fishes based on the trade‐off between offspring survivorship and number. In doing so, we derive quantitative predictions for the relationship of optimal egg size to temperature based on the size and temperature dependences of the growth and mortality, and hence survivorship, of eggs and larvae. Our model shows that smaller eggs are favoured at warmer temperatures largely because egg survivorship declines with both egg size and temperature. The predictions of our model (egg mass in grams = 0.013*e−0.11*T ºC) were comparable to the observed interspecific relationship (0.0029*e−0.09*T ºC; N = 221 spp.). Thus, our results provide insights into how temperature shapes the evolution of egg size in marine teleost fishes.

Effects of embryo energy, egg size, and larval food supply on the development of asteroid echinoderms.

Organisms have limited resources available to invest in reproduction, causing a trade‐off between the number and size of offspring. One consequence of this trade‐off is the evolution of disparate egg sizes and, by extension, developmental modes. In particular, echinoid echinoderms (sea urchins and sand dollars) have been widely used to experimentally manipulate how changes in egg size affect development. Here, we test the generality of the echinoid results by (a) using laser ablations of blastomeres to experimentally reduce embryo energy in the asteroid echinoderms (sea stars), Pisaster ochraceus and Asterias forbesi and (b) comparing naturally produced, variably sized eggs (1.7‐fold volume difference between large and small eggs) in A. forbesi. In P. ochraceus and A. forbesi, there were no significant differences between juveniles from both experimentally reduced embryos and naturally produced eggs of variable size. However, in both embryo reduction and egg size variation experiments, simultaneous reductions in larval food had a significant and large effect on larval and juvenile development. These results indicate that (a) food levels are more important than embryo energy or egg size in determining larval and juvenile quality in sea stars and (b) the relative importance of embryo energy or egg size to fundamental life history parameters (time to and size at metamorphosis) does not appear to be consistent within echinoderms.

Reproduction in the pitviper Bothrops jararacussu: large females increase their reproductive output while small males increase their potential to mate

Reproductive traits vary widely within and among snake species, and are influenced by a range of factors. However, additional studies are needed on several species, especially on tropical snake faunas, to fully understand the patterns of reproductive variation in snakes. Here, we characterized the reproductive biology of B. jararacussu from southeastern and southern Brazil. We combined macroscopic and microscopic examinations of the reproductive system of museum specimens with observations of free-ranging snakes to characterize size at sexual maturity, sexual size dimorphism (SSD), reproductive output, and male and female reproductive cycles. We compared our data with published literature and discuss the factors that may play a role in shaping the reproductive patterns in the species and the genus. Bothrops jararacussu shares several characteristics with its congeners such as autumn mating season, obligatory sperm storage in the female reproductive tract, seasonal timing of parturition (summer-autumn), female-biased SSD, maturity at larger body sizes in females, and a positive relationship between body size and litter size. These characteristics seem phylogenetically conserved in Bothrops. On the other hand, B. jararacussu exhibits some unique characteristics such as a high degree of SSD (one of the highest values recorded in snakes), a large female body size, and a large litter and offspring size, which are among the largest recorded in the genus. Moreover, larger females reproduce more frequently than smaller conspecifics. These characteristics may be collectively interpreted as the result of a strong selection for increased fecundity. Other peculiarities of the species include an asynchrony between spermiogenesis (summer-autumn) and the peak of SSK hypertrophy (autumn to spring) and a prolonged production of SSK granules. Because SSK hypertrophy and mating are androgen-dependent in snakes, the prolonged SSK hypertrophy suggests that male B. jararacussu may prolong their potential to mate (compared with its congeners), which may increase their reproductive success. Our results and previous literature collectively suggest that, in Bothrops, the evolution of SSD is driven by fecundity selection, variation in reproductive output is influenced by variation in female body size, and the timing of spermiogenesis is influenced by other factors in addition to temperature. We also suggest that male Bothrops have undergone multiple evolutionary shifts in the timing of spermiogenesis.

Critical Galton-Watson branching processes with a countable set of types and infinite second moments

We consider an indecomposable Galton-Watson branching process with a countable set of types. Assuming that the process is critical and may have infinite variance of the offspring sizes of some (or all) types of particles we describe the asymptotic behaviour of the survival probability of the process and establish a Yaglom-type conditional limit theorem for the infinite-dimensional vector of the number of particles of all types. Bibliography: 20 titles.

Temporal pattern of offspring release and degree of parental investment in two viviparous asterinid sea stars with an overview of matrotrophy and offspring size variation in echinoderms that care for their offspring

ABSTRACT The temporal pattern of juvenile release by two species of viviparous asterinid sea stars that incubate their young in the gonads was documented. Parvulastra parvivipara released juveniles (400–3000 µm diameter) in 1–5 cohorts. Parents produced large juveniles (>1000-µm) irrespective of adult size. Released juveniles were larger than the retained juveniles. Most Cryptasterina hystera offspring were released in one large clutch of similarly sized juveniles (732-µm mean diameter). After this initial release, the presence of large juveniles (944-µm mean diameter) in the gonads of C. hystera indicates that they are supported by matrotrophy, potentially through sibling cannibalism. The degree of parental investment additional to the egg in both species was estimated by using a matrotrophy index (MI, the ratio of juvenile and egg dry mass). As the eggs of P. parvivipara and C. hystera could not be isolated, the eggs of their congeners (P. exigua and C. pentagona, respectively) were used as a proxy to estimate the MI, the first application of this index to a marine invertebrate. The MI ranged from 597 to 55082 in P. parvivipara and 1.7–6.2 in C. hystera for juveniles across the different size classes. Matrotrophy and size variation of offspring may be characteristics of echinoderms that incubate their young.

Novel sources of (co)variation in nestling begging behavior and hunger at different biological levels of analysis

Abstract Biological hypotheses predicting patterns of offspring begging typically concern the covariance with hunger and/or development at specific hierarchical levels. For example, hunger drives within-individual patterns of begging, but begging also drives food intake among individuals within broods, and begging and food intake can covary positively or negatively among genotypes or broods. Testing biological phenomena that occur at multiple levels, therefore, requires the partitioning of covariance between traits of interest to ensure that each level-specific relationship is appropriately assessed. We performed a partial cross-fostering study on a wild population of great tits (Parus major), then used multivariate mixed models to partition variation and covariation in nestling begging effort and two metrics of nestling hunger within versus among individual nestlings and broods. At the within-individual level, we found that nestlings begged more intensely when hungrier (positive correlation between begging and hunger). However, among individuals, nestlings that were fed more frequently also begged more intensely on average (negative correlation between begging and hunger). Variation in nestling mass did not give rise to the negative correlation between begging and hunger among nestlings, but we did find that lighter nestlings begged more intensely than their heavier biological siblings, suggesting that this effect may be driven by a genetic component linked to offspring size. Our study illustrates how patterns of covariance can differ across biological levels of analysis and addresses biological mechanisms that could produce these previously obscured patterns.

Life History Divergence in Livebearing Fishes in Response to Predation: Is There a Microevolution to Macroevolution Barrier?

A central problem in evolutionary biology is to determine whether adaptive phenotypic variation within species (microevolution) ultimately gives rise to new species (macroevolution). Predation environment can select for trait divergence among populations within species. The implied hypothesis is that the selection resulting from predation environment that creates population divergence within species would continue across the speciation boundary such that patterns of divergence after speciation would be a magnified accumulation of the trait variation observed before speciation. In this paper, we test for congruence in the mechanisms of microevolution and macroevolution by comparing the patterns of life history divergence among three closely related species of the livebearer genus Brachyrhaphis (Poeciliidae), namely B. rhabdophora, B. roseni, and B. terrabensis. Within B. rhabdophora, populations occur in either predator or predator-free environments, and have been considered to be at a nascent stage of speciation. Sister species B. roseni and B. terrabensis are segregated into predator and predator-free environments, respectively, and represent a post-speciation comparison. Male and female size at maturity, clutch size, and offspring size (and to a lesser extent reproductive allocation) all diverged according to predation environment and differences were amplified through evolutionary time, i.e., across the speciation boundary. Variation observed among nascent species differentiated by predation environment is a good predictor of variation among established species differentiated by predation environment. We found no evidence for different processes or different levels of selection acting across the speciation boundary, suggesting that macroevolution in these species can be understood as an accumulation of micro-evolutionary changes.

Opposing fitness consequences of habitat use in a harvested moose population.

Landscape changes are happening at an unprecedented pace, and together with high levels of wildlife harvesting humans have a large effect on wildlife populations. A thorough knowledge of their combined influence on individual fitness is important to understand factors affecting population dynamics. The goal of the study was to assess the individual consistency in the use of risky habitat types, and how habitat use was related to fitness components and life-history strategies. Using data from a closely monitored and harvested population of moose Alces alces, we examined how individual variation in offspring size, reproduction and survival was related to the use of open grasslands; a habitat type that offers high-quality forage during summer, but at the cost of being more exposed to hunters in autumn. The use of this habitat type may therefore involve a trade-off between high mortality risk and forage maximization. There was a high repeatability in habitat use, which suggests consistent behaviour within individuals. Offspring number and weight were positively related to the mothers' use of open grasslands, whereas the probability of surviving the subsequent harvest season was negatively related to the use of the same habitat type. As a consequence, we found a nonsignificant relationship between habitat use and lifetime fitness. The study suggests that harvesting, even if intended to be nonselective with regard to phenotypes, may be selective towards animals with specific behaviour and life-history strategies. As a consequence, harvesting can alter the life-history composition of the population and target life-history strategies that would be beneficial for individual fitness and population growth in the absence of hunting.

Pregnancy-related risk factors for sex cord-stromal tumours and germ cell tumours in parous women: a registry-based study

BackgroundNon-epithelial ovarian cancers are divided into sex cord-stromal tumours (SCSTs) and germ cell tumours (GCTs). Whereas parity and other pregnancy-related factors are protective for epithelial ovarian cancer, their associations with SCSTs and GCTs remains unclear.MethodsUsing data from the medical birth registries from Denmark, Finland, Norway and Sweden, we compared all parous women with a diagnosis of SCSTs (n = 420) or GCTs (n = 345) 1970–2013 with up to 10 parous controls (SCSTs n = 4041; GCTs n = 2942) matched on the cases’ birth year and country. We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) of associations between pregnancy-related factors and SCSTs and GCTs.ResultsThe risk of SCSTs, but not GCTs, decreased with higher age at last birth [≥40 versus <25 years: OR 0.48 (95% CI 0.23–0.98)]. The risk of SCSTs (but not GCTs) also decreased with shorter time since last birth. Number of births, preterm birth, preeclampsia, and offspring size were not associated with risk of SCSTs or GCTs.ConclusionsWe found a decreased risk of SCSTs with higher age at last birth and shorter time since last birth. The risk of SCSTs (but not GCTs) may be influenced by the woman’s reproductive history.

Effect of Neem, Siam Weed and Vetiver Oils on Physiological Reactions and Fitness of House Fly, &lt;I&gt;Musca domestica &lt;/I&gt; L

Insecticidal activities of hexane extracts of leaves and roots of siam weed and vetiver, and roots of neem were assessed against house fly, Musca domestica L. Mortality test was conducted using serial concentrations 20%, 10%, 5% and 2.5% of extracted oils while behavioural orientation of house fly to oil odour, antioviposition effect of oil toward the insects, biochemical reactions in treated flies and fitness of offspring were determined using 20% oil concentration. House fly mortality varied significantly with plant species and part of plant extracted (P &lt; 0.001), concentration applied (P &lt; 0.001) and time post-exposure (P &lt; 0.001). All tested plant extracts showed potential as good control agents with average mortality ranging from 59-74%. However, significantly lower median lethal values (LC50 and LT50) separated vetiver as the most toxic plant against the insect pest. The plant oils repelled house flies (93-100%), reduced the number of larvae that hatched from laid eggs, lowered adult emergence and caused a significant reduction in size and weight of offspring. On the contrary, exposure to plant oils did not alter offspring sex ratio. In comparison to untreated house flies, plant oils induced biochemical stress in poisoned cohorts as evidenced in significant deviation of digestive enzyme (α- and β- amylases, lipase) activity and concentrations of detoxifying enzyme (glutathione-Stransferase), neurochemical enzyme (acetylcholinesterase) and energy metabolism biomolecules (total protein). Implications of obtained results for non-chemical control strategies are discussed.

Geographic variation in maternal investment and trade-offs between egg size and clutch size in an endemic toad of the Qinghai-Tibet Plateau

Life history theory predicts that animals often produce fewer offspring of larger size and indicate a stronger trade-off between the number and size of offspring to cope with increasing environmental stress. In order to evaluate this prediction, we tested the life history characteristics of Bufo minshanicus at eight different altitudes on the eastern Tibetan Plateau, China. Our results revealed a positive correlation between female SVL and clutch size or egg size, revealing that larger females produce more and larger eggs. However, high-altitude toads seem to favor more offspring and smaller egg sizes when removing the effect of female SVL, which is counter to theoretical predictions. In addition, there was an overall significantly negative relationship between egg size and clutch size, indicative of a trade-off between egg size and fecundity. Therefore, we suggest that higher fecundity, rather than larger egg size, is a more effective reproductive strategy for this species of anuran living at high-altitude environments.

Individual variation in parental tradeoffs between the number and size of offspring at the pre‐ and post‐natal stages

Life‐history theory predicts that parents refer to the resources they hold to determine their breeding strategy. In multi‐brooded species, it is hypothesized that single‐brooded parents produce larger clutches and raise offspring with a brood survival strategy, whereas multi‐brooded parents only do this under good breeding conditions. Under poor conditions, they produce smaller clutches and raise offspring with a brood reduction strategy. We tested this hypothesis in the Brown‐cheeked Laughing Thrush Trochalopteron henrici, which can breed twice a year on the Tibetan Plateau, by investigating the life‐history traits and provisioning behaviours of single‐ and double‐brooded parents. Single‐brooded parents laid larger clutches of smaller eggs and produced more and larger fledglings than double‐brooded parents in their first brood. Double‐brooded parents produced smaller clutches of larger eggs but fledged larger nestlings in their first brood than in their second brood. As single‐brooded parents only need to raise one brood a year, then producing and raising as many offspring as possible (i.e. the brood survival strategy in a large brood) can maximize their reproductive success. For double‐brooded parents, producing and raising fewer offspring in the first brood (i.e. the brood survival strategy in a small brood) can ensure their nesting success during a short breeding cycle. Additionally, producing more offspring but raising larger nestlings in the second brood (i.e. the brood reduction strategy in a large brood) can select for offspring of higher quality within the brood. Our findings indicate that different tradeoffs between single‐ and double‐brooded parents in egg‐laying and nestling‐raising may be an adaptation to the seasonal variation in environmental conditions.

Effects of Astaxanthin on Inflammation and Insulin Resistance in a Mouse Model of Gestational Diabetes Mellitus.

Gestational diabetes mellitus (GDM) is a condition in which a hormone made by the placenta prevents the body from using insulin effectively. It is important to find an effective treatment. A mouse model of GDM was used to testify the effects of astaxanthin on glucose tolerance and insulin sensitivity. Production of inflammatory cytokines, reactive oxygen species (ROS), and glucose transporter type 4 (GLUT4) translocation and insulin-related signaling were measured in the presence of astaxanthin both in vivo and in vitro. It was found that astaxanthin improved insulin sensitivity, glucose tolerance, and litter size of offspring and reduced birth weight of offspring and inflammation in GDM mouse. Moreover, astaxanthin increased GLUT4 translocating to membrane without altering its secretion/expression and glucose uptake and consumption in C2C12 skeletal muscle cells. Furthermore, ROS generation and insulin-related signaling inhibited by tumor necrosis factor α was restored by astaxanthin. It is concluded that astaxanthin has the potential to attenuate GDM symptoms by regulating inflammation and insulin resistance in skeletal muscle of pregnant mice. Our findings suggest that astaxanthin could be a promising and effective molecule to treat GDM.