| patterns of postmating reproductive isolation in a newly discovered species pair, aquarius remigis and a. remigoides (hemiptera;gerridae). | aquarius remigoides gallant and fairbairn has recently been described as specifically distinct from a. remigis (say) based upon genetic and morphological data. both species are common, semiaquatic bugs (hemiptera; gerridae) found on the surface of streams and small rivers. allozyme studies have shown them to be more distantly related than most other congeneric species in the gerridae, with significant barriers to gene flow where their ranges abut. we assess postmating reproductive isolation betw ... | 1997 | 9203351 |
| lifetime selection on adult body size and components of body size in a waterstrider: opposing selection and maintenance of sexual size dimorphism. | sexual size dimorphism (ssd), the difference in body size between males and females, is common in almost all taxa of animals and is generally assumed to be adaptive. although sexual selection and fecundity selection alone have often been invoked to explain the evolution of ssd, more recent views indicate that the sexes must experience different lifetime selection pressures for ssd to evolve and be maintained. we estimated selection acting on male and female adult body size (total length) and com ... | 2000 | 10937232 |
| allometry for sexual size dimorphism: testing two hypotheses for rensch's rule in the water strider aquarius remigis. | within any given clade, male size and female size typically covary, but male size often varies more than female size. this generates a pattern of allometry for sexual size dimorphism (ssd) known as rensch's rule. i use allometry for ssd among populations of the water strider aquarius remigis (hemiptera, gerridae) to test the hypothesis that rensch's rule evolves in response to sexual selection on male secondary sexual traits and an alternative hypothesis that it is caused by greater phenotypic p ... | 2005 | 16224713 |
| the form of sexual selection on male genitalia cannot be inferred from within-population variance and allometry - a case study in aquarius remigis. | male genital morphology in insects and arachnids is characterized by static hypoallometry and low intrapopulational levels of phenotypic variation relative to other male traits. the one-size-fits-all model of genital evolution attributes these patterns to stabilizing sexual selection. this model relies on the assumption that the observed patterns of variation and allometry reflect the form of sexual selection acting these traits. we test this by examining the patterns of scaling and trait variat ... | 2007 | 17439615 |
| the effect of ambient humidity and metabolic rate on the gas-exchange pattern of the semi-aquatic insect aquarius remigis. | we have examined the effects of temperature on metabolic rate and respiratory pattern in the water strider aquarius remigis. as temperature was increased from 10 to 30°c, the metabolic rate of the insects increased and the respiratory pattern transitioned from discontinuous, to cyclic, to continuous. the discontinuous gas-exchange cycle (dgc) was observed even in insects standing on water when the respirometry chamber was being perfused with humid (>95% relative humidity) air. comparisons of ins ... | 2011 | 21389192 |
| protease activation and the signal transduction pathway regulating motility in sperm from the water strider aquarius remigis. | many motile processes are regulated such that movement occurs only upon activation of a signaling cascade. sperm from a variety of species are initially quiescent and must be activated prior to beating. the signaling events leading to the activation and regulation of sperm motility are not well characterized. mature seminal vesicle sperm from the water strider aquarius remigis are immotile in vitro, but vigorous motility is activated by trypsin. trypsin-activated motility was blocked by pretreat ... | 2012 | 22278949 |
| aquatic and terrestrial organic matter in the diet of stream consumers: implications for mercury bioaccumulation. | the relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (hg) remain poorly understood. we used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their ph to assess consumer reliance on aquatic (periphyton) vs. terrestrial (riparian vegetation) organic matter, and whe ... | 2012 | 22645815 |
| variation in terrestrial and aquatic sources of methylmercury in stream predators as revealed by stable mercury isotopes. | mercury (hg) is widely distributed in the environment, and its organic form, methylmercury (mehg), can extensively bioaccumulate and biomagnify in aquatic and terrestrial food webs. concentrations of mehg in organisms are highly variable, and the sources in natural food webs are often not well understood. this study examined stable isotope ratios of mehg (mass-dependent fractionation, as δ(202)hgmehg; and mass-independent fractionation, as δ(199)hgmehg) in benthic invertebrates, juvenile steelhe ... | 2014 | 25105808 |
| an interommatidial exocrine gland with a "nail-headed" structure in the water strider aquarius remigis (hemiptera, gerridae). | the fine structure of the interommatidial exocrine glands, found in the compound eyes of the water strider aquarius remigis, is described using light, scanning, and transmission electron microscopy. the glandular pores of the glands are specialized into minute "nail-headed" structures (ns), which are described for the first time in arthropod compound eyes. each ns is composed of two components: a rod-like stalk and a cup-like depression. the tem study shows that the glands are class 3 epidermal ... | 2015 | 26319269 |
| multiple mating reveals complex patterns of assortative mating by personality and body size. | understanding patterns of non-random mating is central to predicting the consequences of sexual selection. most studies quantifying assortative mating focus on testing for correlations among partners' phenotypes in mated pairs. few studies have distinguished between assortative mating arising from preferences for similar partners (expressed by all or a subset of the population) vs. from phenotypic segregation in the environment. also, few studies have assessed the robustness of assortative matin ... | 2016 | 26332682 |
| correlational selection on personality and social plasticity: morphology and social context determine behavioural effects on mating success. | despite a central line of research aimed at quantifying relationships between mating success and sexually dimorphic traits (e.g., ornaments), individual variation in sexually selected traits often explains only a modest portion of the variation in mating success. another line of research suggests that a significant portion of the variation in mating success observed in animal populations could be explained by correlational selection, where the fitness advantage of a given trait depends on other ... | 2017 | 27859289 |
| escape jumping by three age-classes of water striders from smooth, wavy and bubbling water surfaces. | surface roughness is a ubiquitous phenomenon in both oceanic and terrestrial waters. for insects that live at the air-water interface, such as water striders, non-linear and multi-scale perturbations produce dynamic surface deformations which may impair locomotion. we studied escape jumps of adults, juveniles and first-instar larvae of the water strider aquarius remigis on smooth, wave-dominated and bubble-dominated water surfaces. effects of substrate on takeoff jumps were substantial, with sig ... | 2017 | 28546506 |
| developmental changes in biophysical properties of photoreceptors in the common water strider (gerris lacustris): better performance at higher cost. | although the dependence of invertebrate photoreceptor biophysical properties on visual ecology has already been investigated in some cases, developmental aspects have largely been ignored due to the general research emphasis on holometabolous insects. here, using the patch-clamp method, we examined changes in biophysical properties and performance of photoreceptors in the common water strider gerris lacustris during postembryonic development. we identified two types of peripheral photoreceptors, ... | 2014 | 24872534 |
| sexual size dimorphism and selection in the wild in the waterstrider aquarius remigis: lifetime fecundity selection on female total length and its components. | darwin's fecundity advantage model is often cited as the cause of female biased size dimorphism, however, the empirical studies of lifetime selection on male and female body size that would be required to demonstrate this are few. as a component of a study relating sexual size dimorphism to lifetime selection in natural populations of the female size-biased waterstrider aquarius remigis (hemiptera: gerridae), we estimated coefficients for daily fecundity selection, longevity selection, and lifet ... | 1997 | 28565360 |
| body size and fecundity in the waterstrider aquarius remigis: a test of darwin's fecundity advantage hypothesis. | the general female bias in body size of animals is usually attributed to fecundity selection. while many studies have demonstrated a positive relationship between body size and fecundity, the most common interpretation of fecundity selection is that larger females have larger abdomens and can hold more eggs, yet the relationship between abdomen size and fecundity has rarely been examined. for the waterstrider, aquarius remigis, we find a significant relationship between body size and fecundity a ... | 1996 | 28307857 |
| estimating genetic correlations from measurements of field-caught waterstriders. | lynch (1999) proposed a method for estimation of genetic correlations from phenotypic measurements of individuals for which no pedigree information is available. this method assumes that shared environmental effects do not contribute to the similarity of relatives, and it is expected to perform best when sample sizes are large, many individuals in the sample are paired with close relatives, and heritability of the traits is high. we tested the practicality of this method for field biologists by ... | 2001 | 11761071 |
| how well do mating frequency and duration predict paternity success in the polygynandrous water strider aquarius remigis? | the relationship between mating success and paternity success is a key component of sexual selection but has seldom been estimated for species in which both sexes mate with many partners (polygynandry). we used a modification of parker's sterile male technique to measure this relationship for the water strider aquarius remigis in 47 laboratory populations simulating natural conditions of polygynandry. we also tested the hypothesis that prolonged copulation, a characteristic of this species, enha ... | 2002 | 12389726 |
| host age, but not host location within a stream, is correlated with the prevalence of gut parasites in water striders. | we tested for correlations between the geographic, demographic, and temporal distribution of an aquatic insect host and the prevalence of its gut parasites in southwestern ohio. trypanosomatids were present in aquarius remigis collected from all 4 streams surveyed in the watershed. prevalence declined dramatically from may to july and remained low through the fall. this pattern was consistent over all sites of our study, with no effect of stream, stream site (upstream vs. downstream), or host se ... | 2003 | 12880253 |
| biophysics: water-repellent legs of water striders. | water striders (gerris remigis) have remarkable non-wetting legs that enable them to stand effortlessly and move quickly on water, a feature believed to be due to a surface-tension effect caused by secreted wax. we show here, however, that it is the special hierarchical structure of the legs, which are covered by large numbers of oriented tiny hairs (microsetae) with fine nanogrooves, that is more important in inducing this water resistance. | 2004 | 15525973 |
| one tool, many uses: precopulatory sexual selection on genital morphology in aquarius remigis. | while congruent evidence indicates that sexual selection is the most likely selective force explaining the rapid divergence of male genital morphology in insects, the mechanisms involved in this process remain unclear. in particular, little attention has been paid to precopulatory sexual selection. we examine sexual selection for mating success on male genital components in six populations of aquarius remigis, a water strider characterized by unique genital morphology. multivariate selection ana ... | 2005 | 16033567 |
| sexual selection and the evolution of sexual size dimorphism in the water strider, aquarius remigis. | sexual size dimorphism (ssd) is often attributed to sexual selection, particularly when males are the larger sex. however, sexual selection favoring large males is common even in taxa where females are the larger sex, and is therefore not a sufficient explanation of patterns of ssd. as part of a more extensive study of the evolution of ssd in water striders (heteroptera, gerridae), we examine patterns of sexual selection and ssd in 12 populations of aquarius remigis. we calculate univariate and ... | 1996 | 28565700 |
| direct and indirect effects of multiple enemies on water strider mating dynamics. | previous studies have shown that green sunfish, lepomis cyanellus, have strong effects on the activity, habitat use, social interactions and mating dynamics of a stream-dwelling water strider, aquarius remigis (family gerridae, hence, gerrids). in nature, however, stream pools often contain not just sunfish and water striders, but also smaller fish such as minnows. here, we used factorial experiments in seminatural streams to document the direct and indirect effects of sunfish and fathead minnow ... | 1996 | 28307080 |
| why do californian striders fly? | discerning the adaptive significance of migratory strategies poses significant challenges, not the least of which is measuring migratory capability in natural populations. we take advantage of a visible migratory dimorphism to study variation in migratory capability in the stream-dwelling water strider, aquarius remigis. theory predicts loss of migratory capability in this species because streams have been viewed as stable and persistent habitats. as expected, a. remigis lack wings throughout mo ... | 2009 | 18808439 |
| sexual conflict and the energetic costs of mating and mate choice in water striders. | analyses of intersexual conflicts of interest over courtship, mating, or mate guarding require an understanding of the physiological costs of sexual interaction. repeated respirometric measures of energetic expenditure were taken on female aquarius remigis while unladen and while carrying a mating male, a small metal weight, or a euthanized male. unladen "cruising" locomotion consumed an average of 334.6 microw of energy (82 j kg-1 m-1); this estimate of the cost of locomotion coincides with mea ... | 1998 | 18811423 |
| the role of multilevel selection in the evolution of sexual conflict in the water strider aquarius remigis. | in evolution, exploitative strategies often create a paradox in which the most successful individual strategy "within" the group is also the most detrimental strategy "for" the group, potentially resulting in extinction. with regard to sexual conflict, the overexploitation of females by harmful males can yield similar consequences. despite these evolutionary implications, little research has addressed why sexual conflict does not ultimately drive populations to extinction. one possibility is tha ... | 2010 | 20636357 |
| population structure influences sexual conflict in wild populations of water striders. | in sexual conflict, aggressive males frequently diminish the long-term reproductive success of females in efforts to gain a short-term advantage over rival males. this short-term advantage can selectively favour high-exploitation males. however, just as the over-exploitation of resources can lead to local extinction, the over-exploitation of females in the form of harassment by aggressive males can yield similar consequences resulting in reduced female fecundity, increased female mortality and o ... | 2010 | 24049189 |
| assembly of the fluorescent acrosomal matrix and its fate in fertilization in the water strider, aquarius remigis. | animal sperm show remarkable diversity in both morphology and molecular composition. here we provide the first report of intense intrinsic fluorescence in an animal sperm. the sperm from a semi-aquatic insect, the water strider, aquarius remigis, contains an intrinsically fluorescent molecule with properties consistent with those of flavin adenine dinucleotide (fad), which appears first in the acrosomal vesicle of round spermatids and persists in the acrosome throughout spermiogenesis. fluoresce ... | 2011 | 20857404 |
| germ-cell hub position in a heteropteran testis correlates with the sequence and location of spermatogenesis and production of elaborate sperm bundles. | in insects, spermatogonial cells undergo several mitotic divisions with incomplete cytokinesis, and then proceed through meiosis and spermatogenesis in synchrony. the cells derived from a single spermatogonial cell are referred to as a cyst. in the water strider aquarius remigis, spermiogenesis occurs within two bi-lobed testes. in contrast to most insects, in which the germ-cell hub is located apically and sequential stages of spermatogenesis can be seen moving toward the base of the testis, ea ... | 2015 | 25735541 |
| characterization of plasma membrane associated type ii α-d-mannosidase and β-n-acetylglucosaminidase of aquarius remigis sperm. | for successful fertilization to occur, molecules on the surface of male and female gametes must recognize each other in a complementary manner. in some organisms, sperm possess a glycosidase on the plasma membrane overlying the head while eggs have glycoproteins that are recognized by those glycosidases resulting in sperm-egg recognition. in this study, two glycosidases, mannosidase and β-n-acetylglucosaminidase, were identified and biochemically characterized in aquarius remigis sperm. the mann ... | 2015 | 25801709 |
| a scanning electron microscopic study of mechanoreceptors in the walking legs of the water strider, gerris remigis. | | 1973 | 4777779 |
| modified microtubules in the testis of the water strider, gerris remigis (say). | | 1972 | 4552143 |
| histochemical localization of acid phosphatase in the ovary of gerris remigis say (hemiptera). | | 1966 | 6006386 |
| the histology and histochemistry of oogenesis in the water strider, gerris remigis say. | | 1966 | 5927450 |
| microtubular structures associated with the acrosome during spermiogenesis in the water-strider, gerris remigis (say). | | 1966 | 5948721 |
| fine structure of the chromatoid body during spermato-genesis in the water-strider, gerris remigis (say). | | 1965 | 5895738 |
| fitness consequences of alternative life histories in water striders, aquarius remigis (heteroptera: gerridae). | using field and laboratory observations and experiments over 3 years, i investigated whether reproductive trade-offs shape individual life histories in two natural populations of the water strider, aquarius remigis, in which univoltine and bivoltine life cycles coexist. both later eclosion dates and food shortages, even after adult eclosion, induced diapause in females, thus deferring reproduction to the following spring. adult body size was positively affected by food availability during juveni ... | 1994 | 28313630 |
| clinal variation in eastern populations of the waterstrider aquarius remigis: gradual intergradation or discontinuity? | | 1993 | 28567886 |
| genetic population structure and levels of gene flow in the stream dwelling waterstrider, aquarius (=gerris) remigis (hemiptera: gerridae). | gene flow, in combination with selection and drift, determines levels of differentiation among local populations. in this study we estimate gene flow in a stream dwelling, flightless waterstrider, aquarius remigis. twenty-eight aquarius remigis populations from quebec, ontario, new brunswick, iowa, north carolina, and california were genetically characterized at 15 loci using starch gel electrophoresis. sampling over two years was designed for a hierarchical analysis of population structure inco ... | 1992 | 28564034 |
| life-history differences in adjacent water strider populations: phenotypic plasticity or heritable responses to stream temperature? | | 1991 | 28563826 |
| sexual selection for homogamy in the gerridae: an extension of ridley's comparative approach. | ridley (1983) proposed that three factors are necessary and sufficient for the development of positive assortative mating (homogamy) in natural populations. these factors are 1) a correlation between male size and success in competition for mates (intrasexual selection), 2) a correlation between female size and fecundity, and 3) prolonged pairing. in the presence of these three factors, selection will favor males that select large (and thus more fecund) females as mates, thus leading to positive ... | 1988 | 28581084 |
| a test of the hypothesis of compensatory upstream dispersal using a stream-dwelling waterstrider, gerris remigis say. | this paper reports the results of 2 experiments designed to determine if adult gerris remigis (hemiptera, heteroptera), a stream-dwelling waterstrider, tend to disperse preferentially upstream, as predicted by the colonization cycle hypothesis summarized by muller (1982). markrecapture observations and experimental removals were used to assess the distance and direction of movement of adult g. remigis along a small mountain stream, over a full year. these experiments indicated that adult g. remi ... | 1985 | 28310827 |
| the effects of trout on water striders in stream pools. | observations made in rattlesnake creek, santa barbara county, california, u.s.a. indicate that rainbow trout (salmo gairdneri) affect the microdistribution of adult water striders (gerris remigis). gerrids occupied all areas of stream pools lacking trout but stayed in margins of pools containing trout. to test the hypothesis that the presence of trout controlled the distribution of water striders within pools, trout were removed from some pools and transferred to pools lacking trout. undistrubed ... | 1984 | 28311214 |
| sex discrimination in gerris remigis: role of a surface wave signal. | even when blinded with masks, adult male water striders (gerris remigis) accurately ascertain the sex of other adult water striders in the laboratory. freely moving females that were artificially made to play back computer-generated male surface wave and body-contact signals of about 90 waves per second were treated as males by the masked males and as females when no such playbacks were made. thus, the males can use presence or absence of the male signal as the sole means for sex discrimination. | 1979 | 17799643 |
| lipids of the water-strider gerris remigis say (heteroptera: gerridae). seasonal and developmental variations. | | 1975 | 1149432 |