scholarly journals Male clasping ability, female polymorphism and sexual conflict: fine-scale elytral morphology as a sexually antagonistic adaptation in female diving beetles

2013 ◽  
Vol 10 (86) ◽  
pp. 20130409 ◽  
Author(s):  
Kristina Karlsson Green ◽  
Alexander Kovalev ◽  
Erik I. Svensson ◽  
Stanislav N. Gorb
Keyword(s):  
Sexual Conflict ◽  
Adhesive Force ◽  
Beetle Species ◽  
Female Polymorphism ◽  
Diving Beetles ◽  
Males And Females ◽  
Suction Cups ◽  
Female Morph ◽  
Diving Beetle ◽  
Sexually Antagonistic Coevolution

During sexual conflict, males and females are expected to evolve traits and behaviours with a sexually antagonistic function. Recently, sexually antagonistic coevolution was proposed to occur between male and female diving beetles (Dytiscidae). Male diving beetles possess numerous suction cups on their forelegs whereas females commonly have rough structures on their elytra. These rough structures have been suggested to obstruct adhesion from male suction cups during mating attempts. However, some diving beetle species are dimorphic, where one female morph has a rough elytra and the other has a smooth elytra. Here, we used biomechanics to study the adhesive performance of male suction cups on the female morphs in two diving beetle species: Dytiscus lapponicus and Graphoderus zonatus . We compared adhesion on the rough and the smooth female morphs to infer the function of the rough elytral modifications. We found that the adhesive force on the rough structures was much lower than on other surfaces. These findings support the suggestion of sexual conflict in diving beetles and a sexually antagonistic function of the rough female structures. In addition, males differed in their adhesive capacity on different female surfaces, indicating a male trade-off between adhering to smooth and rough female morphs.

scholarly journals Observed shifts in the contact zone between two forms of the diving beetleHydroporus memnoniusare consistent with predictions from sexual conflict

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2089 ◽  
Author(s):  
David T. Bilton ◽  
Garth N. Foster
Keyword(s):  
Contact Zone ◽  
Sexual Conflict ◽  
Climatic Warming ◽  
Population Replacement ◽  
Trade Offs ◽  
Diving Beetles ◽  
Using Data ◽  
Cuticular Surface ◽  
Diving Beetle ◽  
Sexually Antagonistic Coevolution

Sexual conflict drives both inter- and intrasexual dimorphisms in many diving beetles, where male persistence and female resistance traits co-evolve in an antagonistic manner. To date most studies have focussed on species where rough and smooth females and their associated males typically co-occur within populations, where phenotype matching between morphs may maintain forms as stable polymorphisms. The Palaearctic diving beetleHydroporus memnoniusis characterised by having dimorphic (rough var.castaneusand smooth, shining) females and associated males which differ in persistence traits; the two forms being largely distributed parapatrically. In this species, instead of mating trade-offs between morphs, males associated withcastaneusfemales should have a mating advantage with both this form and shining females, due to their increased persistence abilities on either cuticular surface. This may be expected to lead to the replacement of the shining form withcastaneusin areas where the two come into contact. Using data collected over a thirty year period, we show that this process of population replacement is indeed occurring,castaneushaving expanded significantly at the expense of the shining female form. Whilst populations of both forms close to the contact zone appear to differ in their thermal physiology, these differences are minor and suggest that the expansion ofcastaneusis not linked to climatic warming in recent decades. Instead we argue that the observed spread ofcastaneusand its associated male may result from the dynamics of sexually antagonistic coevolution in this beetle.

Sexual Conflict in Human Mating

2017 ◽  
Vol 26 (4) ◽  
pp. 307-313 ◽  
Author(s):  
David M. Buss
Keyword(s):  
Sexual Conflict ◽  
Sexual Exploitation ◽  
Group Living ◽  
Sexual Infidelity ◽  
Sexual Regret ◽  
Opposite Sex ◽  
Living Species ◽  
Males And Females ◽  
Human Mating ◽  
Sexually Antagonistic Coevolution

Despite interdependent reproductive fates that favor cooperation, males and females exhibit many psychological and behavioral footprints of sexually antagonistic coevolution. These include strategies of deception, sexual exploitation, and sexual infidelity as well as anti-exploitation defenses such as commitment skepticism and emotions such as sexual regret and jealousy. Sexual conflict pervades the mating arena prior to sexual consummation, after a mating relationship has formed, and in the aftermath of a breakup. It also permeates many other social relationships in forms such as daughter-guarding, conflict in opposite-sex friendships, and workplace sexual harassment. As such, sexual conflict constitutes not a narrow or occasional flashpoint but rather persistent threads that run through our intensely group-living species.

scholarly journals Predaceous diving beetles (Coleoptera: Dytiscidae) from Montenegro with new records and description of the female of Hydroporus Macedonicus Fery & Pesic, 2006

2011 ◽  
Vol 63 (2) ◽  
pp. 477-485 ◽  
Author(s):  
Ana Pavicevic ◽  
V. Pesic
Keyword(s):  
Present State ◽  
New Records ◽  
Beetle Species ◽  
Ecological Characteristics ◽  
Water Beetle ◽  
Diving Beetles ◽  
The Family ◽  
Aquatic Beetle ◽  
First Time ◽  
Diving Beetle

This paper deals with the aquatic beetle species of the family Dytiscidae collected from various freshwaters habitats in Montenegro. In total 39 water beetle species were collected from 56 localities in Montenegro between 2007 and 2010. Twelve species and one subspecies are reported for the first time for Montenegro: Agabus sturmii (Gyllenhal, 1808), A. paludosus (Fabricius, 1801), Deronectes moestus inconspectus (Leprieur, 1876), D. platynotus (Germar, 1834), Dytiscus circumcinctus Ahrens, 1811, D. dimidiatus Bergstr?sser, 1778, Hydroporus macedonicus Fery & Pesic, 2006, H. pubescens (Gyllenhal, 1808), Ilybius chalconatus (Panzer, 1797), I. fuliginosus fuliginosus (Fabricius, 1792), I. pseudoneglectus (Franciscolo, 1972), Liopterus haemorrhoidalis (Fabricius, 1787) and Nebrioporus luctuosus (Aub?, 1838). The female genitalia of Hydroporus macedonicus Fery & Pesic, 2006, a rare water beetle previously known only from southern Macedonia, are illustrated. The present state of knowledge of the Montenegrin diving beetle fauna and its ecological characteristics is discussed.

The Effects of the sphragis on male and female genitalia in Acraea (Nymphalidae) butterflies

2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho
Keyword(s):  
Interspecific Variation ◽  
Sperm Storage ◽  
Male Mating ◽  
Museum Collections ◽  
Storage Organ ◽  
Mating Plug ◽  
Males And Females ◽  
Comparison And Analysis ◽  
Imagej Software ◽  
Sexually Antagonistic Coevolution

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.

Reproductive behavior

2018 ◽  
Author(s):  
Rachel Olzer ◽  
Rebecca L. Ehrlich ◽  
Justa L. Heinen-Kay ◽  
Jessie Tanner ◽  
Marlene Zuk
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Female Choice ◽  
Reproductive Behavior ◽  
Mating Systems ◽  
Insect Behavior ◽  
Sequential Approach ◽  
Evolutionary Mechanisms ◽  
Anatomy And Physiology ◽  
Males And Females

Sex and reproduction lie at the heart of studies of insect behavior. We begin by providing a brief overview of insect anatomy and physiology, followed by an introduction to the overarching themes of parental investment, sexual selection, and mating systems. We then take a sequential approach to illustrate the diversity of phenomena and concepts behind insect reproductive behavior from pre-copulatory mate signalling through copulatory sperm transfer, mating positions, and sexual conflict, to post-copulatory sperm competition, and cryptic female choice. We provide an overview of the evolutionary mechanisms driving reproductive behavior. These events are linked by the economic defendability of mates or resources, and how these are allocated in each sex. Under the framework of economic defendability, the reader can better understand how sexual antagonistic behaviors arise as the result of competing optimal fitness strategies between males and females.

scholarly journals The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict?

2020 ◽  
Vol 75 (1) ◽  
Author(s):  
Julia A. Kunz ◽  
Guilhem J. Duvot ◽  
Maria A. van Noordwijk ◽  
Erik P. Willems ◽  
Manuela Townsend ◽  
...  
Keyword(s):  
Sexual Conflict ◽  
Sexual Coercion ◽  
High Association ◽  
Sexual Swellings ◽  
Fecal Cortisol ◽  
Habitat Productivity ◽  
Pongo Pygmaeus Wurmbii ◽  
Males And Females ◽  
Study Sites ◽  
The Cost

Abstract Sexual coercion, in the form of forced copulations, is relatively frequently observed in orangutans and generally attributed to their semi-solitary lifestyle. High ecological costs of association for females may be responsible for this lifestyle and may have prevented the evolution of morphological fertility indicators (e.g., sexual swellings), which would attract (male) associates. Therefore, sexual conflict may arise not only about mating per se but also about associations, because males may benefit from associations with females to monitor their reproductive state and attempt to monopolize their sexual activities. Here, we evaluate association patterns and costs for females when associating with both males and females of two different orangutan species at two study sites: Suaq, Sumatra (Pongo abelii), and Tuanan, Borneo (Pongo pygmaeus wurmbii). Female association frequency with both males and females was higher in the Sumatran population, living in more productive habitat. Accordingly, we found that the cost of association, in terms of reduced feeding to moving ratio and increased time being active, is higher in the less sociable Bornean population. Males generally initiated and maintained such costly associations with females, and prolonged associations with males led to increased female fecal cortisol metabolite (FCM) levels at Tuanan, the Bornean population. We conclude that male-maintained associations are an expression of sexual conflict in orangutans, at least at Tuanan. For females, this cost of association may be responsible for the lack of sexual signaling, while needing to confuse paternity. Significance statement Socioecological theory predicts a trade-off between the benefits of sociality and the ecological costs of increased feeding competition. Orangutans’ semi-solitary lifestyle has been attributed to the combination of high association costs and low predation risk. Previous work revealed a positive correlation between association frequencies and habitat productivity, but did not measure the costs of association. In this comparative study, we show that females likely incur costs from involuntary, male-maintained associations, especially when they last for several days and particularly in the population characterized by lower association frequencies. Association maintenance therefore qualifies as another expression of sexual conflict in orangutans, and especially prolonged, male-maintained associations may qualify as an indirect form of sexual coercion.

scholarly journals Soft Hybrid Suction Cup Capable of Sticking to Various Objects and Environments

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 50
Author(s):  
Hideyuki Tsukagoshi ◽  
Yuichi Osada
Keyword(s):  
Vertical Direction ◽  
Check Valve ◽  
Adhesive Force ◽  
Outer Diameter ◽  
Shear Direction ◽  
Concrete Walls ◽  
Suction Force ◽  
Suction Cup ◽  
Valve Function ◽  
Suction Cups

A universal suction cup that can stick to various objects expands the areas in which robots can work. However, the size, shape, and surface roughness of objects to which conventional suction cups can stick are limited. To overcome this challenge, we propose a new hybrid suction cup structure that uses the adhesive force of sticky gel and the suction force of negative pressure. In addition, a flexible and thin pneumatic balloon actuator with a check valve function is installed in the interior, enabling the controllable detachment from objects. The prototype has an outer diameter of 55 mm, a weight of 18.8 g, and generates an adsorption force of 80 N in the vertical direction and 60 N in the shear direction on porous walls where conventional suction cups struggle to adsorb. We confirmed that parts smaller than the suction cup and fragile potato chips are adsorbed by the prototype. Finally, the effectiveness of the proposed method is verified through experiments in which a drone with the prototypes can be attached to and detached from concrete walls and ceilings while flying; the possibility of adsorption to dusty and wet plates is discussed.

scholarly journals Quantifying the gender load: can population crosses reveal interlocus sexual conflict?

2006 ◽  
Vol 361 (1466) ◽  
pp. 363-374 ◽  
Author(s):  
Tristan A.F Long ◽  
Robert Montgomerie ◽  
Adam K Chippindale
Keyword(s):  
Sperm Competition ◽  
Sexual Conflict ◽  
Population Differentiation ◽  
Population Divergence ◽  
Mating Frequency ◽  
Female Reproduction ◽  
Female Fitness ◽  
Antagonistic Coevolution ◽  
The Cost ◽  
Sexually Antagonistic Coevolution

Six sister populations of Drosophila melanogaster kept under identical environmental conditions for greater than 600 generations were reciprocally crossed to investigate the incidence of population divergence in allopatry. Population crosses directly influenced fitness, mating frequency, and sperm competition patterns. Changes in both female remating rate and the outcome of male sperm competition (P 1 , P 2 ) in response to foreign males were consistent with intersexual coevolution. Moreover, seven of the 30 crosses between foreign mates resulted in significant reductions in female fitness, whereas two resulted in significant increases, compared to local matings. This tendency for foreign males to reduce female fitness may be interpreted as evidence for either sexually antagonistic coevolution or the disruption of mutualistic interactions. However, instances in which female fitness improved via cohabitation with foreign males may better reveal sexual conflict, signalling release from the cost of interacting with locally adapted males. By this metric, female reproduction in D. melanogaster is strongly constrained by local adaptation by males, a situation that would promote antagonistic coevolution between the sexes. We conclude that sexual selection can promote population differentiation in allopatry and that sexual conflict is likely to have played a role in population differentiation in this study system.

scholarly journals Sex-dependent dominance maintains migration supergene in rainbow trout

2018 ◽  
Author(s):  
Devon E. Pearse ◽  
Nicola J. Barson ◽  
Torfinn Nome ◽  
Guangtu Gao ◽  
Matthew A. Campbell ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Sex Chromosomes ◽  
Sexual Conflict ◽  
Genetic Basis ◽  
Deleterious Mutation ◽  
Deleterious Mutations ◽  
Heteromorphic Sex Chromosomes ◽  
Males And Females ◽  
Shared Genetic ◽  
Environmental Dependence

AbstractTraits with different fitness optima in males and females cause sexual conflict when they have a shared genetic basis. Heteromorphic sex chromosomes can resolve this conflict and protect sexually antagonistic polymorphisms but accumulate deleterious mutations. However, many taxa lack differentiated sex chromosomes, and how sexual conflict is resolved in these species is largely unknown. Here we present a chromosome-anchored genome assembly for rainbow trout (Oncorhynchus mykiss) and characterize a 56 Mb double-inversion supergene that mediates sex-specific migration through sex-dependent dominance, a mechanism that reduces sexual conflict. The double-inversion contains key photosensory, circadian rhythm, adiposity, and sexual differentiation genes and displays frequency clines associated with latitude and temperature, revealing environmental dependence. Our results constitute the first example of sex-dependent dominance across a large autosomal supergene, a novel mechanism for sexual conflict resolution capable of protecting polygenic sexually antagonistic variation while avoiding the homozygous lethality and deleterious mutation load of heteromorphic sex chromosomes.

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