scholarly journals Food Limitation but Not Enhanced Rates of Ejaculate Production Imposes Reproductive and Survival Costs to Male Crickets

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1498
Author(s):  
Saoirse McMahon ◽  
Magdalena Matzke ◽  
Cristina Tuni
Keyword(s):  
Food Limitation ◽  
Nutrient Deficiency ◽  
Field Cricket ◽  
Male Body ◽  
Adult Males ◽  
Negative Effects ◽  
Trade Offs ◽  
Feeding Regimes ◽  
Future Reproduction ◽  
Poor Nutrition

Estimating costs of ejaculate production is challenging. Metabolic investment in ejaculates may come at the expense of other physiological functions and may negatively affect future reproduction and/or survival. These trade-offs are especially likely to occur under constrained resource pools (e.g., poor nutrition). Here, we investigated costs of ejaculate production via trade-offs in the field cricket Gryllus bimaculatus. We experimentally increased rates of ejaculate production, while keeping an unmanipulated group, in adult males kept at high and low feeding regimes and tested the effects of our treatments on (i) somatic maintenance (i.e., changes in male body mass), (ii) future reproduction (i.e., the likelihood of producing a spermatophore and the viability of its sperm), and (iii) lifetime survival and longevity. We predicted investment in ejaculates to impinge upon all measured responses, especially in low-fed individuals. Instead, we only found negative effects of food limitation, suggesting low or undetectable costs of spermatophore production. High mating rates may select for males to maximize their capacity of ejaculate production, making ejaculate traits less prone to trade-offs with other fitness-related life history traits. Nevertheless, males were impaired due to nutrient deficiency in producing viable ejaculates, suggesting condition-dependent costs for ejaculate production.

Mate availability facilitates cannibalistic behaviour in a nest brooding fish: effects of timing during the brood cycle

Behaviour ◽  
2011 ◽  
Vol 148 (2) ◽  
pp. 247-264 ◽  
Author(s):  
Masanori Kohda ◽  
Nobuhiro Ohnishi ◽  
Noboru Okuda ◽  
Tomohiro Takeyama ◽  
Omar Myint
Keyword(s):  
Laboratory Experiments ◽  
Gravid Female ◽  
Theoretical Models ◽  
Filial Cannibalism ◽  
Mate Availability ◽  
Stimulus Female ◽  
Trade Offs ◽  
Future Reproduction ◽  
Cannibalistic Behaviour ◽  
The Subject

AbstractFilial cannibalism, eating one's own viable offspring, is accepted as an adaptive response to trade-offs between current and future reproduction. Theoretical models predict that high mate availability may induce more filial cannibalism, but this prediction is rarely tested. To examine this prediction, we performed laboratory experiments using the nest breeding goby Rhinogobius flumineus. Subject males were allowed to mate with a gravid female and care for the broods. A separate gravid female housed in a small cage (stimulus-female) was shown to the subject males at one of three different points during the brood cycle: prior to spawning, within 1 day after spawning and 1 week after spawning. Empty cages were shown as a control. Males that were shown the stimulus-female before spawning cannibalised more eggs than control males. In contrast, males that were shown the stimulus-females after spawning cannibalised as few eggs as control males did. Additionally, males that were shown the stimulus-female prior to spawning did not court females more intensively than other males. Thus, we suggest that the presence of an additional mate, rather than energy expenditure associated with courtship directed toward an additional mate, can facilitate males to cannibalise their eggs.

scholarly journals Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Edward R. Ivimey-Cook ◽  
Kris Sales ◽  
Hanne Carlsson ◽  
Simone Immler ◽  
Tracey Chapman ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Dietary Restriction ◽  
Mortality Risk ◽  
Lifespan Extension ◽  
Dietary Interventions ◽  
Negative Effects ◽  
Trade Offs ◽  
Wide Range ◽  
Broad Variety

Dietary restriction (DR) increases lifespan in a broad variety of organisms and improves health in humans. However, long-term transgenerational consequences of dietary interventions are poorly understood. Here, we investigated the effect of DR by temporary fasting (TF) on mortality risk, age-specific reproduction and fitness across three generations of descendants in Caenorhabditis elegans . We show that while TF robustly reduces mortality risk and improves late-life reproduction of the individuals subject to TF (P 0 ), it has a wide range of both positive and negative effects on their descendants (F 1 –F 3 ). Remarkably, great-grandparental exposure to TF in early life reduces fitness and increases mortality risk of F 3 descendants to such an extent that TF no longer promotes a lifespan extension. These findings reveal that transgenerational trade-offs accompany the instant benefits of DR, underscoring the need to consider fitness of future generations in pursuit of healthy ageing.

scholarly journals Molecular Mechanisms and Biochemical Pathways for Micronutrient Acquisition and Storage in Legumes to Support Biofortification for Nutritional Security

2021 ◽  
Vol 12 ◽  
Author(s):  
Manish Roorkiwal ◽  
Sarita Pandey ◽  
Dil Thavarajah ◽  
R. Hemalatha ◽  
Rajeev K. Varshney
Keyword(s):  
Molecular Mechanisms ◽  
Food System ◽  
Significant Risk ◽  
Nutrient Deficiency ◽  
Nutrient Content ◽  
Sub Saharan Africa ◽  
Nutritional Security ◽  
Legume Crops ◽  
Sub Saharan ◽  
Poor Nutrition

The world faces a grave situation of nutrient deficiency as a consequence of increased uptake of calorie-rich food that threaten nutritional security. More than half the world’s population is affected by different forms of malnutrition. Unhealthy diets associated with poor nutrition carry a significant risk of developing non-communicable diseases, leading to a high mortality rate. Although considerable efforts have been made in agriculture to increase nutrient content in cereals, the successes are insufficient. The number of people affected by different forms of malnutrition has not decreased much in the recent past. While legumes are an integral part of the food system and widely grown in sub-Saharan Africa and South Asia, only limited efforts have been made to increase their nutrient content in these regions. Genetic variation for a majority of nutritional traits that ensure nutritional security in adverse conditions exists in the germplasm pool of legume crops. This diversity can be utilized by selective breeding for increased nutrients in seeds. The targeted identification of precise factors related to nutritional traits and their utilization in a breeding program can help mitigate malnutrition. The principal objective of this review is to present the molecular mechanisms of nutrient acquisition, transport and metabolism to support a biofortification strategy in legume crops to contribute to addressing malnutrition.

scholarly journals Positive Correlation between Pesticide Consumption and Longevity in Solitary Bees: Are We Overlooking Fitness Trade-Offs?

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 819
Author(s):  
Verena Strobl ◽  
Domenic Camenzind ◽  
Angela Minnameyer ◽  
Stephanie Walker ◽  
Michael Eyer ◽  
...  
Keyword(s):  
Food Consumption ◽  
False Negative ◽  
Solitary Bees ◽  
Negative Effects ◽  
Physiological Factors ◽  
Positive Correlation ◽  
Agricultural Pesticides ◽  
Negative Results ◽  
Trade Offs ◽  
Survival And Reproduction

The ubiquitous use of pesticides is one major driver for the current loss of biodiversity, and the common practice of simultaneously applying multiple agrochemicals may further contribute. Insect toxicology currently has a strong focus on survival to determine the potential hazards of a chemical routinely used in risk evaluations. However, studies revealing no effect on survival or even indicating enhanced survival are likely to be misleading, if potential trade-offs between survival and other physiological factors are overlooked. Here, we used standard laboratory experiments to investigate the sublethal (i.e., food consumption) and lethal (i.e., survival) effects of two common agricultural pesticides (Roundup® and clothianidin) on adult female solitary bees, Osmia bicornis. The data showed no significant effect of the treatment on cumulative survival; however, a significant positive correlation between herbicide and insecticide exposure and age was revealed, i.e., bees exposed to higher dosages lived longer. As no significant differences in daily food consumption were observed across treatment groups, increased food intake can be excluded as a factor leading to the prolonged survival. While this study does not provide data on fitness effects, two previous studies using solitary bees observed significant negative effects of neonicotinoid insecticides on fitness, yet not on survival. Thus, we conjecture that the observed non-significant effects on longevity may result from a trade-off between survival and reproduction. The data suggest that a focus on survival can lead to false-negative results and it appears inevitable to include fitness or at least tokens of fitness at the earliest stage in future risk assessments.

Influence of wing loading on Colorado potato beetle flight

2004 ◽  
Vol 136 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Chris J.K. MacQuarrie ◽  
Gilles Boiteau ◽  
Dan Quiring
Keyword(s):  
Wing Surface ◽  
Wing Loading ◽  
Physiological Processes ◽  
Trade Offs ◽  
Potato Beetle ◽  
Flight Capacity ◽  
Flight Frequency ◽  
Access To Water ◽  
Potato Foliage ◽  
Poor Nutrition

AbstractFlight of overwintered and summer population Colorado potato beetles, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), with a range of wing loadings was measured following exposure to different quality diets. Beetles fed a diet of insect-resistant foliage expressing Bacillus thuringiensis tenebrioniz toxins, beetles that did not feed but consumed water, and those that were starved without access to water exhibited a lower range of wing loadings than those fed conventional foliage, but there was no corresponding increase in flight frequency. Exposing potato beetles to poor food or no food resulted in a wing-loading range of 50–140 mg/cm2 compared with a range of 80–200 mg/cm2 for beetles fed conventional foliage. No flight was observed when wing loadings were less than 80 mg/cm2 of wing surface, presumably because of other physiological processes associated with poor nutrition and not because of wing loading per se. Overwintered and summer population beetles fed a diet of conventional potato foliage did not take off when wing loading exceeded 150 mg/cm2 of supporting wing surface. Similar trade-offs between flight capacity and consumption of large meals may exist for other insects.

Should I stay or should I go? Complex environments influence the developmental plasticity of flight capacity and flight-related trade-offs

2019 ◽  
Vol 128 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Jordan R Glass ◽  
Zachary R Stahlschmidt
Keyword(s):  
Life History ◽  
Food Availability ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Temperature Variability ◽  
Field Cricket ◽  
Valuable Insight ◽  
Complex Environments ◽  
Trade Offs ◽  
Flight Capacity

Abstract Complex environments, characterized by co-varying factors (e.g. temperature and food availability) may cause animals to invest resources differentially into fitness-related traits. Thus, experiments manipulating multiple environmental factors concurrently provide valuable insight into the role of the environment in shaping not only important traits (e.g. dispersal capacity or reproduction), but also trait–trait interactions (e.g. trade-offs between traits). We used a multi-factorial design to manipulate variation in temperature (constant 28 °C vs. 28 ± 5 °C daily cycle) and food availability (unlimited vs. intermittent access) throughout development in the sand field cricket (Gryllus firmus). Using a univariate approach, we found that temperature variability and unlimited food availability promoted survival, development, growth, body size and/or reproductive investment. Using principal components as indices of resource allocation strategy, we found that temperature variability and unlimited food reduced investment into flight capacity in females. Thus, we detected a sex-specific trade-off between flight and other life-history traits that was developmentally plastic in response to variation in temperature and food availability. We develop an experimental and statistical framework to reveal shifts in correlative patterns of investment into different life-history traits. This approach can be applied to a range of biological systems to investigate how environmental complexity influences traits and trait trade-offs.

The double-edged effects of guanxi on partner opportunism

2019 ◽  
Vol 34 (6) ◽  
pp. 1313-1322 ◽  
Author(s):  
Lu Shen ◽  
Chuang Zhang ◽  
Wenbo Teng
Keyword(s):  
Empirical Test ◽  
Asset Specificity ◽  
Sales Manager ◽  
Future Research ◽  
Control Mechanisms ◽  
Moderating Effects ◽  
Negative Effects ◽  
Content Type ◽  
Trade Offs ◽  
Matched Data

Purpose This study aims to examine the double-edged effects of guanxi on opportunism and the moderating effects of legal enforceability and partner asset specificity. It thus differs from the current literature, which primarily focuses on the benevolent effects of guanxi. Design/methodology/approach Based on matched data collected from 268 sales manager and salesperson dyads, this study tested hypotheses using hierarchical regressions. Findings The empirical test supports the conceptual model and demonstrates two findings. First, guanxi between boundary spanners follows an inverted U-shaped relationship with inter-firm opportunism. Second, both the benefits and drawbacks of guanxi are stronger under the condition of low legal enforceability and high partner asset specificity. Research limitations/implications The study did not untangle guanxi into different dimensions and did not investigate how firms should make trade-offs between the benefits and drawbacks of guanxi. Therefore, future research could further explore this question by using a multidimensional approach. Practical implications The study alerts managers that guanxi is a double-edged sword, so they should complement it with formal control mechanisms, particularly when they are operating in legally inefficient regions or when their partner firm’s asset specificity is high. Originality/value The study offers a more balanced view of guanxi by showing both its positive and negative effects on opportunism. It also uncovers legal enforceability and partner asset specificity as two boundary conditions that influence the curvilinear effects of guanxi on opportunism.

scholarly journals Financial opportunity costs and deaths among close kin are independently associated with reproductive timing in a contemporary high-income society

2020 ◽  
Vol 287 (1919) ◽  
pp. 20192478
Author(s):  
V. Berg ◽  
D. W. Lawson ◽  
A. Rotkirch
Keyword(s):  
High Income ◽  
Reproductive Timing ◽  
Economic Costs ◽  
Wage Penalty ◽  
Income Loss ◽  
Trade Offs ◽  
Career Opportunities ◽  
Evolutionary Demography ◽  
Future Reproduction ◽  
Demographic Theory

Evolutionary demography predicts that variation in reproductive timing stems from socio-ecologically contingent trade-offs between current and future reproduction. In contemporary high-income societies, the costs and benefits of current reproduction are likely to vary by socioeconomic status (SES). Two influential hypotheses, focusing on the parenthood ‘wage penalty’, and responses to local mortality have separately been proposed to influence the timing of parenthood. Economic costs of reproduction (i.e. income loss) are hypothesized to delay fertility, especially among high childhood SES individuals who experience greater opportunities to build capital through advantageous education and career opportunities. On the other hand, relatively low childhood SES individuals experience higher mortality risk, which may favour earlier reproduction. Here, we examine both hypotheses with a representative register-based, multigenerational dataset from contemporary Finland ( N = 47 678). Consistent with each hypothesis, the predicted financial cost of early parenthood was smaller, and mortality among close kin was higher for individuals with lower childhood SES. Within the same dataset, lower predicted adulthood income and more kin deaths were also independently associated with earlier parenthood. Our results provide a robust demonstration of how economic costs and mortality relate to reproductive timing. We discuss the implications of our findings for demographic theory and public policy.

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