Find research datasets worth reusing

Data from: Clustered or scattered? The impact of habitat quality clustering on establishment and early spread

The match between the environmental conditions of an introduction area and the preferences of an introduced species is the first prerequisite for establishment. Yet, introduction areas are usually landscapes, i.e. heterogeneous sets of habitats that are more or less favourable to the introduced species. Because individuals are able to disperse after their introduction, the quality of the habitat surrounding the introduction site is as critical to the persistence of introduced populations as the quality of the introduction site itself. Moreover, demographic mechanisms such as Allee effects or dispersal mortality can hamper dispersal and affect spread across the landscape, in interaction with the spatial distribution of favourable habitat patches. In this study, we investigate the impact of the spatial distribution of heterogeneous quality habitats on establishment and early spread. First, we simulated introductions in one-dimensional landscapes for different dispersal rates and either dispersal mortality or Allee effects. The landscapes differed by the distribution of favourable and less favourable habitats, which were either clustered into few large aggregates of the same quality or scattered into multiple smaller ones. Second, we tested the predictions of simulations by performing experimental introductions of hymenopteran parasitoids (Trichogramma chilonis) in "clustered" and "scattered" microcosm landscapes. Results highlighted two impacts of the clustering of favourable habitat: by decreasing the risks of dispersal from the introduction site to unfavourable habitat early during the invasion, it increased establishment success. However, by increasing the distance between favourable habitat patches, it also hindered the subsequent spread of introduced species over larger areas.

opencc-zeroSep 2019View details →

Data from: Endocrine and metabolic disorders in survivors of childhood cancers and health-related quality of life and physical activity

Context: Childhood cancer survivors experience chronic health conditions that impact health related quality of life (HRQOL) and participation in optimal physical activity. Objective: The study aimed to determine independent effects of endocrine and metabolic disorders on HRQOL and physical activity. Design, Setting, and Patients: Retrospective cohort with longitudinal follow-up of survivors of childhood cancer enrolled in the North American Childhood Cancer Survivor Study. Main Outcome Measures: Medical Outcomes Short Form-36 estimated HRQOL while participation in physical activity was dichotomized as meeting or not meeting recommendations from the Center for Disease Control and Prevention. Log binomial regression evaluated the association of each endocrine/metabolic disorder with HRQOL scales and physical activity. Results: Of 7,287 survivors, median age 32 years (18-54) at their last follow-up survey, 4,884 (67%) reported one or more endocrine/metabolic disorders. Survivors with either disorder were significantly more likely to be male, older, received radiation treatment, and experience other chronic health conditions. After controlling for covariates, survivors with any endocrine/metabolic disorder were more likely to report poor physical function risk ratio ([RR] 1.25; 95% confidence interval [CI] 1.05-1.48), increased bodily pain (RR 1.27; CI 1.12-1.44), poor general health (RR 1.49; CI 1.32-1.68) and lower vitality (RR 1.21; CI 1.09-1.34) compared to survivors without. The likelihood of meeting recommended physical activity was lower among survivors with growth disorders (RR 0.90; CI=0.83-0.97), osteoporosis (RR 0.87; CI=0.76-0.99), and overweight/obesity (RR 0.92; CI 0.88-0.96). Conclusion: Endocrine and metabolic disorders are independently associated with poor HRQOL and sub-optimal physical activity among childhood cancer survivors.

opencc-zeroSep 2019View details →

Data from: No evidence of positive assortative mating for genetic quality in fruit flies

In sexual populations the effectiveness of selection will depend on how gametes combine with respect to genetic quality. If gametes with deleterious alleles are likely to combine with one another, deleterious genetic variation can be more easily purged by selection. Assortative mating, where there is a positive correlation between parents in a phenotype of interest such as body size, is often observed in nature, but does not necessarily reveal how gametes ultimately combine with respect to genetic quality itself. We manipulated genetic quality in fruit fly populations using an inbreeding scheme designed to provide an unbiased measure of mating patterns. While inbred flies had substantially reduced reproductive success, their gametes did not combine with those of other inbred flies more often than expected by chance, indicating a lack of positive assortative mating. Instead, we detected a negative correlation in genetic quality between parents, i.e., disassortative mating, which diminished with age. This pattern is expected to reduce the genetic variance for fitness, diminishing the effectiveness of selection. We discuss how mechanisms of sexual selection could produce a pattern of disassortative mating. Our study highlights that sexual selection has the potential to either increase or decrease genetic load.

opencc-zeroDec 2012View details →

Data from: Poor resource quality lowers transmission potential by changing foraging behaviour

Resource quality can have conflicting effects on the spread of disease. High quality resources could hinder disease spread by promoting host immune function. Alternatively, high quality food might enhance the spread of disease through other traits of hosts or parasites. Thus, to assess how resource quality shapes epidemics, we need to delineate mechanisms by which food quality affects key epidemiological traits. Here, we disentangle effects of food quality on 'transmission potential' – a key component of parasite fitness that combines transmission rate and parasite production – using a zooplankton host and fungal parasite. We estimated the components of transmission potential (i.e., parasite encounter rate, susceptibility, and yield of parasite propagules) for hosts fed a high quality green alga and a low quality cyanobacterium. A focal experiment was designed to disentangle food quality effects on various components of transmission potential. The low quality resource decreased transmission potential by stunting host growth and altering foraging behaviour. Hosts reared on low quality food were smaller and had lower size-corrected feeding rates. Due to their slower grazing, they encountered fewer parasite spores in the water. Smaller hosts also had lower risk of an ingested spore causing infection (i.e., lower susceptibility), and yielded fewer parasite propagules. Hosts switched from high to low quality food during spore exposure also had low transmission potential – despite their large size – because the poor quality resource strongly depressed foraging. A follow-up experiment investigated traits of the low quality resource that might have driven those results. Cyanobacterial compounds that can inhibit digestive proteases of a related grazer likely did not cause the observed reductions in transmission potential. Our study highlights the value of using mechanistic models to pinpoint how resource quality can change transmission potential. Overall, our results show that low quality resources could inhibit the spread of disease through effects on multiple components of transmission potential. They also provide insight into how disease outbreaks in wildlife may respond to shifts in resource quality caused by eutrophication or climate change.

opencc-zeroDec 2013View details →

Data from: Heterogeneity in individual quality and reproductive trade-offs within species

Interspecifically, a reasonable body of evidence supports a trade-off between offspring size and number. However, at the intraspecific level, a whole manner of phenotypic correlations between offspring size and number are observed. These correlations may be predicted when heterogeneity in resource availability, or quality, is considered. Making the assumption that maternal size is a proxy for resource availability, we meta-analytically quantified four phenotypic reproductive correlations within numerous species: (1) maternal size and offspring size, (2) maternal size and offspring number, (3) offspring number and offspring size, and (4) offspring number and offspring size after controlling for maternal size. Within species, maternal size showed a positive correlation with both offspring size and number. Despite this consistency, no correlation between offspring size and number was found. After controlling for maternal size, however, offspring size and number showed a significant negative correlation. A phylogenetic component of our analysis accounted for little heterogeneity in the data, suggesting that our findings show remarkable consistency across taxa. Overall, our results support an observable phenotypic trade-off between offspring size and number. However, this analysis also highlights the importance of considering quality when examining trade-offs, a task that is not always straightforward as quality is context dependant.

Data from: Differential allocation revisited: when should mate quality affect parental investment?

Differential allocation (DA) is the adaptive adjustment of reproductive investment (up or down) according to partner quality. A lack of theoretical treatments has led to some confusion in the interpretation of DA in the empirical literature. We present a formal framework for DA that highlights the nature of reproductive benefits versus costs for females mated to males of different quality. Contrary to popular belief, analytical and stochastic dynamic models both show that additive benefits of male quality on offspring fitness have no effect on optimal levels of female investment and thus cannot produce DA. Instead, if offspring fitness is affected multiplicatively by male quality, or male quality affects the female cost function, DA is expected because of changes in the marginal benefits or costs of extra investment. Additive male quality effects on the female cost function can cause a novel form of weak DA, because reduced costs can slightly favor current over future reproduction. Combinations of these distinct effects in more realistic model scenarios can explain various patterns of positive and negative DA reported for different species and mating systems. Our model therefore sheds new light on the diversity of empirical results by providing a strong conceptual framework for the differential allocation hypothesis.

Data from: A high quality pedigree and genetic markers both reveal inbreeding depression for quality but not survival in a cooperative mammal

Inbreeding depression, the reduced fitness of offspring of closely related parents, is commonplace in both captive and wild populations and has important consequences for conservation and mating system evolution. However, because of the difficulty of collecting pedigree and life history data from wild populations, relatively few studies have been able to compare inbreeding depression for traits at different points in the life cycle. Moreover, pedigrees give the expected proportion of the genome that is identical by descent (IBDg) whereas in theory with enough molecular markers realised IBDg can be quantified directly. We therefore investigated inbreeding depression for multiple life-history traits in a wild population of banded mongooses using pedigree-based inbreeding coefficients (fped) and standardised multilocus heterozygosity (sMLH) measured at 35-43 microsatellites. Within an information theoretic framework, we evaluated support for either fped or sMLH as inbreeding terms and used sequential regression to determine whether the residuals of sMLH on fped explain fitness variation above and beyond fped. We found no evidence of inbreeding depression for survival, either before or after nutritional independence. By contrast, inbreeding was negatively associated with two quality related traits, yearling body mass and annual male reproductive success. Yearling body mass was associated with fped but not sMLH, while male annual reproductive success was best explained by both fped and residual sMLH. Thus, our study not only uncovers variation in the extent to which different traits show inbreeding depression, but also reveals trait-specific differences in the ability of pedigrees and molecular markers to explain fitness variation and suggests that for certain traits genetic markers may capture variation in realised IBDg above and beyond the pedigree expectation.

opencc-zeroDec 2014View details →

Data from: Effects of gestational maternal undernutrition on growth, carcass composition and meat quality of rabbit offspring

An experiment was conducted in order to evaluate the effects of gestational undernutrition of rabbit does on growth, carcass composition and meat quality of the offsprings. Thirty primiparous non lactating rabbit does were artificially inseminated and randomly divided in three treatment groups: Control (C; fed to 100% of maintenance requirements throughout gestation, n = 10), early undernourished (EU; fed to 50% of maintenance requirements during days 7–19 of gestation, n = 10) and late undernourished (LU; fed to 50% of maintenance requirements during days 20-27 of gestation, n = 10). During the 4th week of the gestation period, LU does significantly lost weight compared to C and EU groups (P<0.05). At kindling, C does produced litters with higher proportions of stillborn kits (P<0.05) while the total litter size (alive and stillborn kits) was not different among groups (10.7, 12.8 and 12.7 kits in C, EU and LU groups, respectively). Kit birth weight tended to be lower in the LU group. During fattening, body weight and feed intake were not different among offsprings of the three experimental groups. Moreover, the maternal undernutrition did not have any impact on carcass composition of the offsprings in terms of carcass parts and internal organs weights as well as meat quality of L. lumborum muscle (pH24, colour, water holding capacity and shear values) at slaughter (70 days of age). Therefore, it can be concluded that the gestational undernutrition of the mother does not have detrimental effects on the productive and quality traits of the offsprings.

opencc-zeroJun 2019View details →

Data from: Subsidy type and quality determine direction and strength of trophic cascades in arthropod food web in agro‐ecosystems

1. The subsidy hypothesis states that communities receiving nutrient subsidies will demonstrate top-down trophic cascades where predators indirectly increase plant biomass. This has been both confirmed and refuted, which might depend on whether the subsidy has mainly targeted the plant or the detrital food-web compartment, and on the subsidy quality. This is particularly poorly understood for terrestrial communities such as heavily subsidized agroecosystems. 2. Using cages covering 4 m2 of ground in a long-term agricultural fertilisation experiment, we tested whether subsidies targeting the detrital soil meso-fauna compartment with organic fertilisers, or the plants with mineral fertiliser, impacted the direction and strength of trophic cascades in an arthropod-plant food-web. We expected top-down controls of generalist arthropod predators (spiders, ground and rove beetles) on aphid densities to be stronger in organically fertilised plots due to enhanced alternative prey availability in the soil. Bottom-up control from barley quality on aphids was anticipated to be stronger in the mineral treatments. We examined how the quality (decomposability) of the organic subsidy governed the cascades by comparing treatments with labile (manure) and recalcitrant (hay) organic matter. 3. Top-down forces dominated in food-webs receiving organic subsidies, while bottom-up forces dominated under mineral fertilisation. A high quality, easily degradable organic subsidy propagated faster through the food-chain, leading to a top-down trophic cascade with generalist predators having a positive effect on plant biomass in the labile but not in the recalcitrant organic treatment. 4. Synthesis and applications: Management of agricultural soils that bolster the soil meso-fauna, e.g. adding organic fertilisers, has potential to increase top-down biological control by naturally occurring generalist arthropod predators. Barley biomass was enhanced in the manure treatment in the presence of arthropod predators to a level comparable to that of mineral fertiliser.

opencc-zeroDec 2014View details →

Data from: Quantity over quality: light intensity, but not red/far-red ratio, affects extrafloral nectar production in Senna mexicana var. chapmanii

Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and insects and provides plants with a form of indirect defense against herbivory. Understanding sources of variation in EFN production is important because such variations affect the number and identity of insect visitors and the effectiveness of plant defense. Light represents a potentially crucial tool for regulating resource allocation to defense, as it not only contributes energy but may help plants to anticipate future conditions. Low red/far-red (R/FR) light ratios can act as a signal of the proximity of competing plants. Exposure to such light ratios has been shown to promote competitive behaviors that coincide with reduced resource allocation to direct chemical defenses. Little is known, however, about how such informational light signals might affect indirect defenses such as EFN, and the interactions that they mediate. Through controlled glasshouse experiments, we investigated the effects of light intensity, and R/FR light ratios, on EFN production in Senna mexicana var. chapmanii. Plants in light-limited conditions produced significantly less EFN, and leaf damage elicited increased EFN production regardless of light conditions. Ratios of R/FR light, however, did not appear to affect EFN production in either damaged or undamaged plants. Understanding the effects of light on indirect defenses is of particular importance for plants in the threatened pine rockland habitats of south Florida, where light conditions are changing in predictable ways following extensive fragmentation and subsequent mismanagement. Around 27% of species in these habitats produce EFN and may rely on insect communities for defense.

Data from: Pre-basic molt, feather quality and modulation of the adrenocortical response to stress in two populations of Rufous-collared sparrows, Zonotrichia capensis

Molt is an energetically expensive process in which birds may allocate 25% or more of their body protein mass to the production of new feathers. Stressful events can interfere with feather growth via the adrenal hormone corticosterone, which is released in response to environmental stress. Corticosterone release, in turn, regulates gluconeogenesis which could directly inhibit protein synthesis and deposition during molt when feathers are growing, which potentially could reduce feather quality dramatically. Thus, many species suppress the adrenocortical stress response, and therefore maintain lower corticosterone levels during molt. In this study we assessed the relationship between plasma corticosterone levels and feather quality in rufous-collared sparrow inhabiting the valleys of the Atacama Desert – one of the most stable and aseasonal environments in the world, and in the semiarid and seasonal Fray Jorge National Park in the north of Chile. We tested two hypotheses; i) feather quality is positively related to the amount of corticosterone suppression during molt, relative to corticosterone levels during other life history stages; and, ii) feather quality is negatively related to the absolute levels of corticosterone. We found negative associations between corticosterone levels and feather quality. However, these effects were stronger in the Atacama Desert where birds showed minimal corticosterone suppression and overall low feather quality. Although we found better feather quality in Fray Jorge, corticosterone suppression in these birds was relatively low in comparison with other species inhabiting higher latitudes. It is possible that birds in a highly variable environment face a stronger trade-off between feather quality and the stress-response. Our results suggest that the strength of the trade-off between feather quality and corticosterone levels could be dependent on energetic demands, seasonality, and unpredictable events.

opencc-zeroDec 2018View details →

Data from: Evolution of age at primiparity in pinnipeds in the absence of the quality-quantity trade-off in reproduction

Age at primiparity (AP) is a key life history trait which is crucial to the evolution of life-history strategies. This trait is particularly interesting in pinnipeds (walrus, eared seals and true seals), which are monotocous animals. Thus, the commonly observed trade-off between offspring quality and quantity does not apply to this taxon. Therefore, comparative studies on the evolution of AP might shed light on other important evolutionary correlates when litter size is fixed. Using phylogenetic generalised least squares analyses, we found a strong negative and robust correlation between relative birth mass (mean pup birth mass as a proportion of mean adult female mass) and AP. Rather than trading-off an early start of reproduction with light relative offspring mass, this result suggests that pinnipeds exhibit either faster (i.e. higher relative offspring mass leading to shorter lactation length, and thus shorter inter-birth interval) or slower life histories and that an early AP and a heavy relative offspring mass co-evolved into a comparatively fast life history strategy. On the other hand, AP was positively related to lactation length: a later start of reproduction was associated with a longer lactation length. Consequently, variation in AP in pinnipeds seems to be affected by an interplay between costs and benefits of early reproduction mediated by relative investment into the single offspring via relative birth mass and lactation length.

Data from: Bottom-up and trait-mediated effects of resource quality on amphibian parasitism

Leaf litter subsidies are important resources for aquatic consumers like tadpoles and snails, causing bottom-up effects on wetland ecosystems. Recent studies have shown that variation in litter nutritional quality can be as important as litter quantity in driving these bottom-up effects. Resource subsidies likely also have indirect and trait-mediated effects on predation and parasitism, but these potential effects remain largely unexplored. We generated predictions for differential effects of litter nutrition and secondary polyphenolic compounds on tadpole (Lithobates sylvatica) exposure and susceptibility to Ribeiroia ondatrae, based on ecological stoichiometry and community-ecology theory. We predicted direct and indirect effects on key traits of the tadpole host (rates of growth, development and survival), the trematode parasite (production of the cercaria infective stages) and the parasite's snail intermediate host (growth and reproduction). To test these predictions, we conducted a large-scale mesocosm experiment using a natural gradient in the concentrations of nutrients (nitrogen) and toxic secondary compounds (polyphenolics) of nine leaf litter species. To differentiate between effects on exposure vs. susceptibility to infection, we included multiple infection experiments including one with constant per capita exposure. We found that increased litter nitrogen increased tadpole survival, and also increased cercaria production by the snail intermediate hosts, causing opposing effects on tadpole per capita exposure to trematode infection. Increased litter polyphenolics slowed tadpole development, leading to increased infection by increasing both their susceptibility to infection and the length of time they were exposed to parasites. Based on these results, recent shifts in forest composition towards more nitrogen-poor litter species should decrease trematode infection in tadpoles via density- and trait-mediated effects on the snail intermediate hosts. However, these shifts also involve increased abundance of litter species with high polyphenolic levels, which should increase trematode infection via trait-mediated effects on tadpoles. Future studies will be needed to determine the relative strength of these opposing effects in natural wetland communities.

opencc-zeroDec 2015View details →

Data from: Impaired sperm quality, delayed mating but no costs for offspring fitness in crickets winning a fight

The outcome of male-male contest competition is known to affect male mating success and is believed to confer fitness benefits to females through preference for dominant males. However, by mating with contest winners, females can incur significant costs spanning from decreased fecundity to negative effects on offspring. Hence identifying costs and benefits of male dominance on female fitness is crucial to unravel the potential for a conflict of interests between the sexes. Here we investigated males' pre- and post-copulatory reproductive investment and its effect on female fitness after a single contest a using the field cricket Gryllus bimaculatus. We allowed males to fight, and immediately measured their mating behaviour, sperm quality, and offspring viability. We found that males experiencing a fight, independently of the outcome, delayed matings but their courtship effort was not affected. However, winners produced sperm of lower quality (viability) compared to losers and to males that did not experience fighting. Results suggest a trade-off in resource allocation between pre- and post-mating episodes of sexual selection. Despite lower ejaculate quality we found no fitness costs (fecundity and viability of offspring) for females mated to winners. Overall our findings highlight the importance of considering fighting ability when assessing male reproductive success, as winners may be impaired in their competitiveness at a post-mating level.

Data from: Early life nutritional quality effects on adult memory retention in a parasitic wasp

Nutritional quality during early life can affect learning ability and memory retention of animals. Here we studied the effect of resource quality gained during larval development on the learning ability and memory retention of 2 sympatric strains of similar genetic background of the parasitoid Trichogramma brassicae: one uninfected and one infected by Wolbachia. Wolbachia is a common arthropod parasite/mutualistic symbiont with a range of known effects on host fitness. Here we studied, for the first time, the interaction between resource quality and Wolbachia infection on memory retention and resource acquisition. Memory retention of uninfected wasps was significantly longer when reared on high quality hosts when compared to low quality hosts. Furthermore, uninfected wasps emerging from high quality hosts showed higher values of protein and triglyceride than those emerging from low quality hosts. In contrast, the memory retention for infected wasps was the same irrespective of host quality, although retention was significantly lower than uninfected wasps. No significant effect of host quality on capital resource amount of infected wasps was observed, and infected wasps displayed a lower amount of protein and triglyceride than uninfected wasps when reared on high quality hosts. This study suggests that the nutritional quality of the embryonic period can affect memory retention of adult wasps not infected by Wolbachia. However, by manipulating the host's obtained capital resource amount, Wolbachia could enable exploitation of the maximum available resources from a range of hosts to acquire suitable performance in complex environments.

Data from: Predictions of response to temperature are contingent on model choice and data quality

The equations used to account for the temperature dependence of biological processes, including growth and metabolic rates are the foundations of our predictions of how global biogeochemistry and biogeography change in response to global climate change. We review and test the use of 12 equations used to model the temperature dependence of biological processes across the full range of their temperature response, including supra- and sub-optimal temperatures. We focus on fitting these equations to thermal response curves for phytoplankton growth, but also tested the equations on a variety of traits across a wide diversity of organisms. We found that many of the surveyed equations have comparable abilities to fit data and equally high requirements for data quality (number of test temperatures and range of response captured), but lead to different estimates of cardinal temperatures and of the biological rates at these temperatures. When these rate estimates are used for biogeographic predictions, differences between the estimates of even the best fitting models can exceed the global biological change predicted for a decade of global warming. As a result, studies of the biological response to global changes in temperature must make careful consideration of model selection and of the quality of the data used for parametrizing these models.

opencc-zeroDec 2012View details →

Data from: Fractal geometry of a complex plumage trait reveals bird's quality

Animal coloration is key in natural and sexual selection, playing significant roles in intra- and interspecific communication because of its linkage to individual behaviour, genetics and physiology. Simple animal traits such as the area or the colour intensity of homogeneous patches have been profusely studied. More complex patterns are widespread in nature, but they escape our understanding because their variation is difficult to capture effectively by standard, simple measures. Here, we used fractal geometry to quantify inter-individual variation in the expression of a complex plumage trait, the heterogeneous black bib of the red-legged partridge (Alectoris rufa). We show that a higher bib fractal dimension (FD) predicted better individual body condition, as well as immune responsiveness, which is condition-dependent in our study species. Moreover, when food intake was experimentally reduced during moult as a means to reduce body condition, the bib's FD significantly decreased. Fractal geometry therefore provides new opportunities for the study of complex animal colour patterns and their roles in animal communication.

Data from: No mutual mate choice for quality in zebra finches: time to question a widely-held assumption

Studies of mate choice typically assume that individuals prefer high quality mates and select them based on condition-dependent indicator traits. In species with bi-parental care, mutual mate choice is expected to result in assortative mating for quality. When assortment is not perfect, the lower quality pair members are expected to compensate by increased parental investment to secure their partner (positive differential allocation). This framework has been assumed to hold for monogamous species like the zebra finch (Taeniopygia guttata), but progress has been hampered by the difficulty to define individual quality. By combining multiple measures of causes (inbreeding, early nutrition) and consequences (ornaments, displays, fitness components) of variation in quality into a single principal component, we here show that quality variation can be quantified successfully. We further show that variation in quality indeed predicts individual pairing success, presumably because it reflects an individual's vigor or ability to invest in reproduction. However, despite high statistical power, we found no evidence for either assortative mating or for positive differential allocation. We suggest that zebra finch ornaments and displays are not sufficiently reliable for the benefits of choosiness to exceed the costs of competition for the putative best partner. To assess the generality of these findings unbiased quantification of signal honesty and preference strength is required, rather than selective reporting of significant results.

Data from: Female nutritional condition affects ovarian fluid quality in guppies

Male and female gametes are often embedded in fluids that are produced by gonads and other reproductive tissues. Female reproductive fluids, usually called ovarian fluids (OF), which often constitute a relevant volumetric component of the egg mass, are rich in ions, sugars, and proteins, and are involved in several functions, from protecting gametes to facilitating fertilization, and often act as mediators of postmating sexual selection. Despite their applied and evolutionary importance, we know virtually nothing about the costs of female reproductive fluid production. We investigated the effect of nutritional condition on OF quality by experimentally manipulating the diet of two groups of female guppies (Poecilia reticulata) which were maintained for 20 days either at a restricted diet or had ad-libitum access to food. In this species, OF enhances sperm swimming longevity and velocity (a predictor of sperm competition success) and mediates postcopulatory inbreeding avoidance. We found that sperm velocity was significantly lower in the OF of diet-restricted females, indicating that OF quality is dependent on female nutritional condition. Our results demonstrate that OF represents non-trivial component of female reproductive investment and provide a tool to investigate which OF constituents are involved in modulating OF-sperm interactions and fertilization.