Stress coping styles and learning in alternative reproductive tactics in male swordtails

Alternative reproductive tactics (ARTs) represent distinct behavioural phenotypes to maximize reproductive success within the same sex, primarily males, and may be genetically and/or conditionally determined. Across animals, intragenerational determinants of conditional ARTs are relatively well understood but transgenerational (non‐genetic) effects of parental ARTs on filial ARTs are largely unknown. Here, we assessed parental effects of conditional male ARTs on sons' ARTs in arrhenotokous spider mites Tetranychus urticae. Arrhenotoky, that is, males arising from unfertilized and females from fertilized eggs, sets the stage for sexual and transgenerational conflicts between male mates and females and their sons. Male ARTs of T. urticae are dichotomous, fighting and sneaking, and apparent in male–male combat and pre‐copulatory guarding behaviour. Due to haplodiploidy, male ARTs can only exert non‐genetic effects on sons of their mates. We hypothesized that parental ART effects are likely to occur in T. urticae because maternal ART mating status (unmated, sneaker‐ or fighter‐mated) is indicative of the offspring' social environment and ART flexibility rather prevails in younger than older males. Fighter‐mated mothers produced more offspring than unmated mothers and had a more daughter‐biased offspring sex ratio than unmated and sneaker‐mated mothers. Sons of fighter‐mated mothers were more likely to guard and did so earlier than sons of unmated and sneaker‐mated mothers. Unmated and sneaker‐mated, but not fighter‐mated, mothers produced sneaker sons that were quicker to start guarding than were fighter sons. Proximately, parental ART effects on sons' ARTs were most likely mediated by differences in seminal fluids. Ultimately, observed alterations of sons' ARTs represent adaptive maternal responses to ART phenotypes rather than manipulation by male mates. Fighter‐mated mothers tuned filial ARTs to male‐competitive environments whereas unmated and sneaker‐mated mothers tuned them to benign environments. Observed alterations in reproductive traits of fighter‐mated mothers suggest adaptive manipulation by the fighter phenotype or aligned male and female interests. Overall, our study documents previously unknown transgenerational ART effects on haploid sons' ARTs. A free Plain Language Summary can be found within the Supporting Information of this article.

Alternative reproductive behaviour, in which individuals of one sex adopt different ways to reproduce, is observed in all major taxa, including mammals, amphibians, insects, and particularly fishes. In order to study ecological conditions for emergence of alternative reproductive tactics (ARTs), we developed an embodied evolution framework incorporating ecological features, such as body size and energy maintenance, where male and female robotic agents naturally face both intersexual and intrasexual interactions for survival and reproduction. We performed simulation experiments in environments with different conditions (food density, reproductive cost, and male-female ratio) and found that ARTs emerged both in males and females. Males evolved three kinds of alternative tactics: fixed, genetically distinct ARTs, in which dominant and sneaker males that differ in body size adopt different tactics to gain access to females, conditionally flexible ARTs, in which individuals change tactics according to body size, and mixed ARTs, in which combinations of genetically fixed and conditionally flexible ARTs are employed. Females evolved two genetically distinct ARTs: quality-oriented female, QoF, and number-oriented female, NoF, in which females increase fitness either by offspring quality or quantity, respectively. Analysis of results confirms the experimental notions that genetically fixed male ARTs are strongly affected by intensity of sexual selection. Conditionally flexible male ARTs are significantly affected by competition level, and female ARTs are mainly affected by food availability. To our knowledge, this study is the first to demonstrate emergence of ARTs in both males and females from an initially monomorphic population in a simulated, embodied evolution framework.

In Atlantic salmon, as in most salmonids, males can mature early in the life cycle, as small freshwater fish, termed parr, and/or undergo a sea migration before maturing as full–size adults. The alternative life histories are contingent on environmental and social circumstances, such as growth rate, territory quality or any other factor that affects the individual9s state. In order to model the choice of life history in this group of commercially valuable species, it is necessary to understand not only the relative contribution of the different male types to subsequent generations, but also to know the factors that affect reproductive success in each type. In this paper we present the results of a study designed to investigate the factors that affect the reproductive success of mature parr. We used highly polymorphic minisatellite DNA markers to analyse paternity in a series of mating experiments where the number and body size of parr were manipulated. The fraction of eggs fertilized by mature parr ranged from 26 to 40 per cent, with individual parr fertilizing up to 26 per cent of the eggs. A strong positive correlation was found between parr size and reproductive success. The relative success of parr decreased with increasing parr number. Data from this and other studies on variation in the timing and degree of parr reproductive success are discussed in relation to the evolution of male mating strategies and life history in salmonids.

Flexibility – reversible phenotypic changes in physiology, morphology, and / or behaviour – has been extensively studied in the framework of alternative reproductive tactics (ARTs). A reproductive tactic is a phenotype that results from a strategy – a decision rule based on genetic program. The relative plasticity hypothesis states that environmentally-induced hormonal changes cause the development of one out several possible ARTs. However, causality between hormones and ARTs has been poorly studied. Further, it is important to determine which environmental factors influence hormonal changes in males of different ARTs to determine in how far these hormonal changes are flexible. In this thesis, I experimentally studied the role of testosterone in causing physiological, morphological, and behavioural differences between two alternative reproductive tactics in male African striped mice, Rhabdomys pumilio: 1) group-living helpers showing alloparental care, low testosterone levels, and high corticosterone levels. 2) solitary-living roamers showing no parental care, high testosterone levels, and low corticosterone levels. Finally, I tested the flexibility of prolactin secretion as prolactin may play a role in the regulation of ARTs. For this, I studied the role of photoperiod and food availability in regulating prolactin levels of paternal dominant breeding males. In chapter 1 I studied which factors correlate with alloparental care. For the first time I demonstrated that both male and female, juvenile and adult philopatrics show extensive helping behaviour (14.7 % of their time). Corticosterone levels correlated with alloparental care in an age- and sex-dependent manner. Natural variation of testosterone levels between helpers did not correlate with alloparental care, suggesting that changes in alloparental care after the tactic switch are not caused by testosterone. In chapter 2, I tested whether an experimental increase of testosterone in male group living helpers influenced alloparental care and dispersal-like behaviours. An experimental increase of testosterone in male group-living helpers did not reduce alloparental care nor aggressive behaviour, but increased boldness, decreased anxiety, and lowered basal corticosterone levels. In the field, exogenous testosterone did not cause dispersal, but it caused male group-living helpers to expand their home ranges (chapter 3). I suggested that an increase of testosterone facilitate dispersal by reducing stress reactivity (low corticosterone levels and low anxiety). Exogenous testosterone also induced sexual maturation and spermatogenesis – testosterone-treated male group-living helpers became scrotal and showed larger testes and epididymis (chapter 3). Thus, I suggested that a quick increase of testosterone levels is an important event during the tactic switch to cause necessary physiological, morphological, and behavioural changes in group-living helpers to disperse and become solitary-living roamers. In chapter 4 I showed that free-ranging paternal dominant breeding males showed higher prolactin levels when they were breeding compared to the non-breeding season, independently whether this was during spring (increase of photoperiod) or during summer, i.e. normal non-breeding season (decrease of photoperiod). Food availability correlated with prolactin levels, suggesting that cues related to food availability may regulate prolactin levels. As paternal dominant breeding males have higher reproductive success than males following an alternative reproductive tactic (i.e. group-living helpers and solitary-living roamers), flexibility in prolactin secretion seems adaptive. My thesis demonstrated that testosterone plays an important role in physiological, morphological and behavioural differences between males of different ARTs in African striped mice. I also showed that the role of environmental factors (e.g. food availability) is crucial in hormonal flexibility (prolactin levels). Thus, studies from the African striped mouse suggest a complex relationship between hormonal and environmental factors in the regulation of ARTs. For future studies, I discussed how to integrate environmental factors in the behavioural endocrinology approach to study proximate mechanisms of ARTs.

This study has attempted to find the teaching methods for the elementary students with low science achievement by examining the differences of science learning motivation, academic stress and stress coping styles and the characteristics shown in the relationship between them. To achieve this, the differences of science learning motivation, academic stress and stress coping styles of the elementary students with low science achievement and their relationship was set up as a study problem. A science learning motivation using a science learning motivation questionnaire reconfigured with PALS along with underachievers diagnosis were measured targeting 660 elementary students located in Seoul. Using an academic stress questionnaire and stress coping style questionnaire, an academic stress and stress coping styles were measured. The results of analyzing the collected data are as follows. First, a science learning motivation of elementary students with low science achievement was lower than the general students but the academic stress was shown higher. Especially, the self-efficacy of science learning motivation was significantly lower and the school stress was highest. For stress coping styles, a tendency of passive and avoidment coping styles were shown higher than the general students. Second, among the science learning motivation of elementary students with low science achievement, the self-efficacy motivation and school stress have shown a negative correlation but had a positive correlation with the goal-oriented motivation centered on ability. In the correlation between the science learning motivation of elementary students with low science achievement and the stress coping styles, the pursuit of social support coping styles have shown a significant positive correlation with the science learning motivation and its subcategories. As a result of conducting a regression analysis on the influence of academic stress and stress copying styles on the science learning motivation of elementary students with low science achievement, among the academic stresses, the school stress was shown to have the biggest influence. Among the stress coping styles, the pursuit of social support coping styles had the biggest influence on the science learning motivation followed by active coping behaviors, passive and avoidment coping behaviors. Low science learning motivation as underachievement factors of elementary students with low science achievement was identified as having a relationship with high school stress and undesirable stress copying styles. Therefore, guidance and a program are required for the elementary student with low science achievement to have desirable stress coping methods on the stressful situations. In addition, for the improvement of science learning motivation, a learning environment is needed for the elementary students with low science achievement with seeking of relevant educational methods.

Personalities are not associated with different reproductive tactics in male Cape ground squirrels, Xerus inauris

Two spatial tactics are usually distinguished in males of Calopteryx damselflies: territorial and nonterritorial. These tactics are believed to underlie two alternative condition-dependent reproductive tactics in these insects, and territorial males are believed to copulate more often. With age, males become weaker, turn nonterritorial, and only occasionally manage to copulate. However, the details of space use by damselflies are poorly known, which hinders the interpretation of the existing empirical data. We describe the space use by individually marked males of the banded demoiselle C. splendens studied during three field seasons in Vladimir Province, Russia. Each male on each day of observations was characterized as either territorial or non-territorial, and the sites of encounter were mapped. The probability of being territorial declined with the male’s age. The spatial tactics (territorial vs. non-territorial) on a given day strongly influenced the tactics used on the following day. We identified the territorial and non-territorial phases in the life of a male damselfly, which occurred consecutively and had a roughly similar duration. During the territorial phase, the male occupied a certain territory and tried to hold it as long as possible. The male abandoned its territory in two cases: (1) when it was driven onto a different territory as the result of competition with other males, or (2) when it was exhausted and became non-territorial. Thus, the space use by the male changed predictably during its life. Therefore, direct comparison of morphological or other characteristics in territorial vs. non-territorial males, frequently made in the literature, makes little sense. Further progress in studying the so-called “alternative reproductive tactics” in damselflies may be more successfully achieved by comparing individual life trajectories of different males (e.g. duration of territorial and non-territorial periods, the number of consecutively occupied territories, etc.). We performed correlation analysis and found that the above parameters did not depend on the wing and abdomen length of the males.

Coupling between stress coping style and time of emergence from spawning nests in salmonid fishes: Evidence from selected rainbow trout strains (Oncorhynchus mykiss)

ABSTRACTIn many animal species, males may exhibit one of several discrete, alternative ways of obtaining fertilisations, known as alternative reproductive tactics (ARTs). Males exhibiting ARTs typically differ in the extent to which they invest in traits that improve their mating success, or the extent to which they face sperm competition. This has led to the widespread prediction that males exhibiting ARTs associated with a high sperm competition risk, or lower investment into traits that improve their competitiveness before mating, should invest more heavily into traits that improve their competitiveness after mating, such as large ejaculates and high‐quality sperm. However, despite many studies investigating this question since the 1990s, evidence for differences in sperm and ejaculate investment between male ARTs is mixed, and there has been no quantitative summary of this field. Following a systematic review of the literature, we performed a meta‐analysis examining how testes size, sperm number and sperm traits differ between males exhibiting ARTs that face either a high or low sperm competition risk, or high or low investment in traits that increase mating success. We obtained data from 92 studies and 67 species from across the animal kingdom. Our analyses showed that male fish exhibiting ARTs facing a high sperm competition risk had significantly larger testes (after controlling for body size) than those exhibiting tactics facing a low sperm competition risk. However, this effect appears to be due to the inappropriate use of the gonadosomatic index as a body‐size corrected measure of testes investment, which overestimates the difference in testes investment between male tactics in most cases. We found no significant difference in sperm number between males exhibiting different ARTs, regardless of whether sperm were measured from the male sperm stores or following ejaculation. We also found no significant difference in sperm traits between males exhibiting different ARTs, with the exception of sperm adenosine triphosphate (ATP) content in fish. Finally, the difference in post‐mating investment between male ARTs was not influenced by the extent to which tactics were flexible, or by the frequency of sneakers in the population. Overall, our results suggest that, despite clear theoretical predictions, there is little evidence that male ARTs differ substantially in investment into sperm and ejaculates across species. The incongruence between theoretical and empirical results could be explained if (i) theoretical models fail to account for differences in overall resource levels between males exhibiting different ARTs or fundamental trade‐offs between investment into different ejaculate and sperm traits, and (ii) studies often use sperm or ejaculate traits that do not reflect overall post‐mating investment accurately or affect fertilisation success.

Chapter Seven - Intralocus Tactical Conflict and the Evolution of Alternative Reproductive Tactics

BackgroundUnder strong sexual selection, certain species evolve distinct intrasexual, alternative reproductive tactics (ARTs). In many cases, ARTs can be viewed as environmentally-cued threshold traits, such that ARTs coexist if their relative fitness alternates over the environmental cue gradient. Surprisingly, the chemical ecology of ARTs has been underexplored in this context. To our knowledge, no prior study has directly quantified pheromone production for ARTs in a male-polymorphic species. Here, we used the bulb mite—in which males are either armed fighters that kill conspecifics, or unarmed scramblers (which have occasionally been observed to induce mating behavior in other males)—as a model system to gain insight into the role of pheromones in the evolutionary maintenance of ARTs. Given that scramblers forgo investment into weaponry, we tested whether scramblers produce higher quantities of the putative female sex-pheromone α-acaridial than fighters, which would improve the fitness of the scrambler phenotype through female mimicry by allowing avoidance of aggression from competitors. To this end, we sampled mites from a rich and a poor nutritional environment and quantified their production of α-acaridial through gas chromatography analysis.ResultsWe found a positive relationship between pheromone production and body size, but males exhibited a steeper slope in pheromone production with increasing size than females. Females exhibited a higher average pheromone production than males. We found no significant difference in slope of pheromone production over body size between fighters and scramblers. However, scramblers reached larger body sizes and higher pheromone production than fighters, providing some evidence for a potential female mimic strategy adopted by large scramblers. Pheromone production was significantly higher in mites from the rich nutritional environment than the poor environment.ConclusionFurther elucidation of pheromone functionality in bulb mites, and additional inter- and intrasexual comparisons of pheromone profiles are needed to determine if the observed intersexual and intrasexual differences in pheromone production are adaptive, if they are a by-product of allometric scaling, or diet-mediated pheromone production under weak selection. We argue chemical ecology offers a novel perspective for research on ARTs and other complex life-history traits.

Alternative reproductive tactics (ARTs), discrete phenotypic variations evolved to maximize fitness, may entail different cost‐benefit trade‐offs. In large mammals, differences in costs associated with ARTs—including energy expenditure and parasite infection—are typically greatest during the breeding season. Nonetheless, physiological and behavioral differences between ARTs can manifest throughout the year, possibly involving costs that may contribute to maintain ARTs within populations. Using the number of nematode larvae per gram of feces (LPG) as a proxy, we explored the temporal changes in lung parasite infection in territorial and nonterritorial male chamois Rupicapra in the Gran Paradiso National Park (Italy), between 2011 and 2012. We aimed to identify which tactic‐specific physiological and behavioral features (including age, hormonal levels, inter‐ and intrasexual interactions, and space use) or climatic factors (temperature and precipitation) best explained yearly variation in parasite infection within and between ARTs. Generalized additive mixed models showed that the fecal larval counts of lung nematodes underwent strong temporal changes in both male types. Differences between ARTs (with higher LPG values in territorial than nonterritorial males) were greatest during the rut and—to a lesser extent—in spring, respectively, at the peak and at the onset of territoriality. The difference in LPG between tactics was largely explained by the greater levels of hormone metabolites in territorial males during the rut. The other variables did not contribute significantly to explain the different shedding of larvae within and between ARTs. Our analysis suggests that different values of LPG between territorial and nonterritorial males are largely a result of tactic‐specific differences in the secretion of hormone metabolites, but only during the rut. To clarify whether rut‐related parasitism contributes to the maintenance of ARTs, tactic‐specific life history trade‐offs, for example, between reproduction and parasite‐related mortality, must be investigated.

Alternative reproductive tactics (ARTs) are discrete reproductive phenotypes governed by decision rules called strategies. ARTs are fixed for life in species with alternative strategies, while tactic expression is plastic in species with a single strategy. ARTs have been investigated in males of many species, but few studies have tested whether the same theoretical framework applies in females. Female striped mice (Rhabdomys pumilio) employ three ARTs: communal breeders give birth in a nest shared with female kin and a breeding male and show allo-parental care; returners give birth away from the shared nest and later return to it; and solitary breeders give birth away from the shared nest and do not return to the group. Here, studying free-living female striped mice over six breeding seasons, we tested whether ARTs arise from alternative strategies or a single strategy. We also asked to what extent stochastic extrinsic factors explain whether individuals become solitary rather than group living. Females switched tactics, consistent with a single strategy, so we tested whether this represented a mixed or conditional single strategy. Only the latter predicts differences between ARTs in traits indicating competitive ability, such as body mass or age, before individuals adopt a tactic. We weighed females at conception when they were still group living to eliminate potential confounding effects of gestation and subsequent social tactic (solitary versus group living) on body mass. Females that went on to use a solitary ART were heavier than those that became communal breeders and returners, in support of a conditional strategy. Solitary breeders also arose through extrinsic factors (mortality of all adult female group members). They weighed less than females that became solitary while relatives were alive, but did not differ in body mass from communal breeders and returners. We conclude that ART theory applies to both sexes, with female striped mice following a conditional single strategy. Future studies should consider the possibility that phenotypes that superficially resemble evolved tactics might also arise through non-adaptive extrinsic causes.

Objective To explore the stress coping style and anxiety status of intensive care unit (ICU) and general ward( referred to as ward) nurses and the relation between stress coping style and anxiety status.Methods Totals of 84 ICU nurses and 77 ward nurses were investigated with general information questionnaire,coping style questionnaire(CSQ) and self rating anxiety scale ( SAS),and compared coping factors score,influencing factors,anxiety incidence and degree between ICU group and ward group,and analysed the relation between stress coping style and anxiety status.Results The “seeking help” (mature coping style)score of ICU nurses group was ( 0.694 ± 0.175 ) higher than ( 0.631 ± 0.212 ) in ward group,and the score of immature style “self-accusation” in ICU group was ( 0.262 ± 0.237 ) lower than ( 0.349 ± 0.262 ) in ward group,difference was statistically significant ( t =2.043,- 2.220,respectively; P ＜ 0.05 ).There was no significant difference in anxiety incidence was found,but anxiety score of ICU group was(39.37 ± 8.905 ) lower than ward group(42.53 ± 8.573 ),and the difference was statistically significant ( t =- 2.292,P ＜ 0.05 ).Coping style was no relation with age,professional title in ICU group( r =-0.060,-0.054,respectively;P ＞ 0.05),while coping style was negatively correlated with age,professional title in ward group( r =-0.237,-0.251,respectively; P ＜ 0.05 ).“solving problem”,“seeking help” were negatively correlated with anxiety (r=-0.267,-0.177,respectively; P ＜ 0.05 or P ＜ 0.01 ).“Shirk”,“self-accusation” and “illusion”( immature coping styles) and “rationalization” ( combined coping style) were positively correlated with anxiety (r =0.329,0.304,0.330,0.287,respectively;P ＜ 0.01 ).Conclusions Improving coping style of nurses can help to reduce nurses' psychological stress and anxiety. Key words: Nurse; Anxiety; Intensive care unit; Coping style ; General ward

Alternative reproductive tactics (ARTs) describe non-reversible or flexible alternative strategies that secure fertilization. For example, some male defend territories with females while others attempt sneaky matings. Often, ARTs are considered to be status-dependent and are explained by differences in mass or competitive ability. However, most studies on ARTs only approximate their fitness effect, ignore males that never reproduced and consider status (e.g. weight) as the sole mediator of ARTs. We used 244 male mice, Mus musculus domesticus, from semi-natural populations, to describe ARTs in Mus Musculus for the first time. We followed males throughout their life and categorized them as territorials or roamers over multiple monthly intervals, after validating our method of assigning tactics with detailed spatial data. We explored if tactic choice is repeatable, whether multiple social and/or intrinsic factors predict tactic choice and transitions between tactics, and tested for fitness and physiological differences between ARTs. Tactic choice was repeatable, but males switched flexibly between tactics. Tactic choice was associated with mass, age, the operational sex ratio and population size. Territorials had a higher probability of reproduction, but a lower gonadosomatic index. Our results reveal a personality component of ARTs, confirm equal mean fitness among tactics and suggest tactic choice as a multifaceted decision under various selective pressures.