scholarly journals Successive matings produce opposite patterns on ejaculate volume and spermatozoa number in an ancient arthropod model with indirect sperm transfer

2019 ◽  
Vol 97 (7) ◽  
pp. 579-587 ◽  
Author(s):  
D.E. Vrech ◽  
M.A. Oviedo-Diego ◽  
P.A. Olivero ◽  
A.V. Peretti
Keyword(s):  
Body Size ◽  
Sperm Competition ◽  
Male Body ◽  
Mating Status ◽  
Trunk Length ◽  
The Third ◽  
Female Mating ◽  
Terrestrial Arthropods ◽  
Factors Influencing ◽  
Sperm Depletion

The production of spermatophore and ejaculate is energetically expensive for males. High mating rates may accelerate sperm depletion and progressively decrease the size of the ejaculates. Sperm competition can shape spermatozoon numbers according to different signals and cues such as number of potential rivals or female mating status. Factors influencing patterns of sperm allocation have been neglected in terrestrial arthropods that transfer sperm indirectly using a complex sclerotized spermatophore deposited on the soil. We used the Neotropical scorpion Bothriurus bonariensis (C.L. Koch, 1842) to examine ejaculate volume, spermatozoon number, and spermatophore’s trunk length along three successive matings and their relationship with body size of males. Males mated and deposited a pre-insemination spermatophore every 10 days. Ejaculate volume and trunk length decreased, whereas spermatozoon number increased over matings. Male body size positively influenced ejaculate volume and trunk length interacted with mating event. High mating rates may decrease ejaculate volume. Sperm competition may produce increased spermatozoon number. Ejaculates are more energetically expensive than spermatozoa and larger males may better face the energetic requirements. Larger spermatophore trunks contain bigger ejaculate volume in the first two mating events, but this relationship disappears at the third mating event. Our discussion focuses on the factors responsible for the observed patterns.

Sperm competition and fertilization success in Atlantic cod (Gadus morhua): effect of sire size and condition factor on gamete quality

1999 ◽  
Vol 56 (12) ◽  
pp. 2315-2323 ◽  
Author(s):  
Ana Rakitin ◽  
Moira M Ferguson ◽  
Edward A Trippel
Keyword(s):  
Body Size ◽  
Sperm Competition ◽  
Gadus Morhua ◽  
Condition Factor ◽  
Atlantic Cod ◽  
Sperm Quality ◽  
Fertilization Success ◽  
Male Body ◽  
Single Female ◽  
Male Condition

Sperm competition experiments were conducted to test the null hypothesis that sperm quality is not affected by male body size in Atlantic cod (Gadus morhua). Genetic markers (allozymes) were used to determine the proportion of larvae sired by pairs of males when their sperm was combined with eggs of a single female simultaneously. Significant differences in fertilization success between males were not explained by differences in body size. Fertilization success was positively associated with male condition factor (K) and with spermatozoa density in each male's semen when equal volumes of semen from each male were used. Male K was positively associated with male fertilization success when the volume of semen used from each male was adjusted to add approximately equal numbers of spermatozoa from each male. The relative fertilization success of males varied depending on which female was the egg donor, suggesting that female "choice" at the gamete level may be occurring in cod.

scholarly journals Contrasting female mate preferences for red coloration in a fish

2019 ◽  
Vol 66 (4) ◽  
pp. 425-433 ◽  
Author(s):  
Charel Reuland ◽  
Brett M Culbert ◽  
Alessandro Devigili ◽  
Ariel F Kahrl ◽  
John L Fitzpatrick
Keyword(s):  
Mate Choice ◽  
Mate Preferences ◽  
Male Body ◽  
Mating Status ◽  
Female Mating ◽  
Ample Opportunity ◽  
Choice Assay ◽  
Beak Size ◽  
Association Time ◽  
Red Coloration

Abstract Understanding how animals select their mates requires knowing the factors that shape mate preferences. Recent theoretical and empirical considerations suggest that female mating status can influence the degree to which a female engages in mate choice, with virgin females predicted to be less choosy than mated females. In this study, we investigated mate choice in both virgin and mated females in the pygmy halfbeak Dermogenys collettei. Halfbeaks are small, live-bearing, internally fertilizing freshwater fish that live in mixed-sex groups where females have ample opportunity to engage in mate choice. Using a dichotomous choice assay, we quantified and contrasted in virgin and mated females mate preferences for differences in male body size, beak size, and area of yellow and red coloration. We also examined how mating status influenced the amount of time a female associated with the first male encountered and the relative amount of time a female associated with each male. We demonstrate that mate preferences of female halfbeaks are driven primarily by the size of red coloration present on males. Females showed contrasting preferences based on mating status, with virgin females preferentially associating with drab males whereas mated females preferentially associate with males possessing large areas of red. Contrary to expectations, female mating status did not influence how females associate with the first males encountered or how females biased their association time among males. Although the precise drivers of these effects need further studying, our finding highlights a possible explanation for how variation in male ornamentation can be maintained.

Body Dissatisfaction: The Ideal Body and a Summary of Theories of Development and Maintenance

2020 ◽  
Author(s):  
Daniel Talbot
Keyword(s):  
Body Size ◽  
Body Dissatisfaction ◽  
Muscle Tone ◽  
Subjective Evaluation ◽  
Male Body ◽  
Ideal Body ◽  
Physiological Outcomes ◽  
The Ideal

Body dissatisfaction can be defined as a negative subjective evaluation of one’s body as a whole, or relating to specific aspects of one’s body such as body size, shape, muscularity/muscle tone, and weight. Prior research has found that body dissatisfaction is associated with a number of negative psychological and physiological outcomes. This commentary describes the Western ideal male body, as well as providing a summary of theories of the cause and maintenance of male body dissatisfaction.

scholarly journals Chest beats as an honest signal of body size in male mountain gorillas (Gorilla beringei beringei)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Edward Wright ◽  
Sven Grawunder ◽  
Eric Ndayishimiye ◽  
Jordi Galbany ◽  
Shannon C. McFarlin ◽  
...  
Keyword(s):  
Body Size ◽  
Competitive Ability ◽  
Dominance Rank ◽  
Male Body ◽  
Honest Signal ◽  
Sexual Competition ◽  
Mountain Gorillas ◽  
Temporal Characteristics ◽  
Gorilla Beringei Beringei ◽  
Vocal Signals

AbstractAcoustic signals that reliably indicate body size, which usually determines competitive ability, are of particular interest for understanding how animals assess rivals and choose mates. Whereas body size tends to be negatively associated with formant dispersion in animal vocalizations, non-vocal signals have received little attention. Among the most emblematic sounds in the animal kingdom is the chest beat of gorillas, a non-vocal signal that is thought to be important in intra and inter-sexual competition, yet it is unclear whether it reliably indicates body size. We examined the relationship among body size (back breadth), peak frequency, and three temporal characteristics of the chest beat: duration, number of beats and beat rate from sound recordings of wild adult male mountain gorillas. Using linear mixed models, we found that larger males had significantly lower peak frequencies than smaller ones, but we found no consistent relationship between body size and the temporal characteristics measured. Taken together with earlier findings of positive correlations among male body size, dominance rank and reproductive success, we conclude that the gorilla chest beat is an honest signal of competitive ability. These results emphasize the potential of non-vocal signals to convey important information in mammal communication.

Sperm Competition and the Dynamics of X Chromosome Drive: Stability and Extinction

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1721-1731 ◽  
Author(s):  
Jesse E Taylor ◽  
John Jaenike
Keyword(s):  
Sex Ratio ◽  
Sperm Competition ◽  
X Chromosome ◽  
Sex Chromosome ◽  
Basin Of Attraction ◽  
Male Mating ◽  
Male And Female ◽  
Mating Rate ◽  
Female Mating ◽  
Balanced Polymorphism

AbstractSeveral empirical studies of sperm competition in populations polymorphic for a driving X chromosome have revealed that Sex-ratio males (those carrying a driving X) are at a disadvantage relative to Standard males. Because the frequency of the driving X chromosome determines the population-level sex ratio and thus alters male and female mating rates, the evolutionary consequences of sperm competition for sex chromosome meiotic drive are subtle. As the SR allele increases in frequency, the ratio of females to males also increases, causing an increase in the male mating rate and a decrease in the female mating rate. While the former change may exacerbate the disadvantage of Sex-ratio males during sperm competition, the latter change decreases the incidence of sperm competition within the population. We analyze a model of the effects of sperm competition on a driving X chromosome and show that these opposing trends in male and female mating rates can result in two coexisting locally stable equilibria, one corresponding to a balanced polymorphism of the SR and ST alleles and the second to fixation of the ST allele. Stochastic fluctuations of either the population sex ratio or the SR frequency can then drive the population away from the balanced polymorphism and into the basin of attraction for the second equilibrium, resulting in fixation of the SR allele and extinction of the population.

Intra- and intersexual selection on male body size in the annual killifish Austrolebias charrua

2013 ◽  
Vol 96 ◽  
pp. 20-26 ◽  
Author(s):  
Carlos Passos ◽  
Bettina Tassino ◽  
Marcelo Loureiro ◽  
Gil G. Rosenthal
Keyword(s):  
Body Size ◽  
Male Body ◽  
Male Body Size ◽  
Annual Killifish

Sexual size dimorphism in the American rubyspot: male body size predicts male competition and mating success

2007 ◽  
Vol 73 (6) ◽  
pp. 987-997 ◽  
Author(s):  
M.A. Serrano-Meneses ◽  
A. Córdoba-Aguilar ◽  
V. Méndez ◽  
S.J. Layen ◽  
T. Székely
Keyword(s):  
Body Size ◽  
Mating Success ◽  
Sexual Size Dimorphism ◽  
Male Competition ◽  
Male Body ◽  
Size Dimorphism ◽  
Male Body Size

scholarly journals A new species of Kurixalus from western Yunnan, China (Anura, Rhacophoridae)

ZooKeys ◽  
2018 ◽  
Vol 770 ◽  
pp. 211-226 ◽  
Author(s):  
Guohua Yu ◽  
Hong Hui ◽  
Dingqi Rao ◽  
Junxing Yang
Keyword(s):  
New Species ◽  
Body Size ◽  
Outer Edge ◽  
Male Body ◽  
Male Body Size ◽  
Western Yunnan ◽  
A New Species

A new species of the genus Kurixalus (Anura: Rhacophoridae) is described from western Yunnan, China. Genetically the new species, Kurixalusyangi sp. n., is closer to Kurixalusnaso than to other known congeners. Morphologically the new species is distinguished from all other known congeners by a combination of the following characters: smaller ratios of head, snout, limbs, IND, and UEW to body size; male body size larger than 30 mm; curved canthus rostralis; weak nuptial pad; brown dorsal color; absence of large dark spots on surface of upper-middle abdomen; presence of vomerine teeth; gold brown iris; single internal vocal sac; serrated dermal fringes along outer edge of limbs; granular throat and chest; rudimentary web between fingers; and presence of supernumerary tubercles and outer metacarpal tubercle.

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