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1.
Frode Skarstein Ivar Folstad Ståle Liljedal Mats Grahn 《Behavioral ecology and sociobiology》2005,57(4):374-380
Genes of the major histocompatibility complex (MHC) are remarkably polymorphic. Several selection mechanisms have been invoked to account for this diversity, including disassortative mating preferences. In addition, eggs may discriminate between sperm based on MHC. To investigate the effects of MHC-genotype on fertilization success, we obtained mature gametes from ripe Arctic charr (Salvelinus alpinus) males and females captured on spawning grounds. The eggs of each female were divided into two batches, and by letting each of 2 males fertilize 1 of the batches, we obtained a total of 36 half-sibling batch-pairs. The semen was diluted to ensure that the two males in each half-sibling batch-pair contributed with the same number of sperm cells. We found that MHC-heterozygous males had significantly higher fertilization success than MHC-homozygous males and neither initial spermatocrit, sperm motility nor swimming velocity co-varied with difference in fertilization success. There was no effect of female genotype or female-male MHC-similarity on fertilization success. However, one MHC-allele was associated with increased fertilization success. It seems plausible that the difference in fertilization success between homo- and heterozygous males may be due to MHC-dependent sperm selection by the ovum.Communicated by M. Abrahams 相似文献
2.
Charlyn Partridge Ingrid Ahnesjö Charlotta Kvarnemo Kenyon B. Mobley Anders Berglund Adam G. Jones 《Behavioral ecology and sociobiology》2009,63(3):345-354
The last several decades of research in behavioral ecology have resulted in a deeper appreciation of post-mating processes
and sexual conflict in sexual selection. One of the most controversial aspects of sexual selection is cryptic mate choice.
Here, we take advantage of male pregnancy in a sex-role-reversed pipefish (Syngnathus typhle) to quantify cryptic choice based on perceived parasite load and other sources of variance in female fitness. Studies have
shown that S. typhle males preferentially mate with females with lower parasite loads and that a male’s perception of female parasite load can
be altered by tattooing females. We manipulated the apparent parasite load of females in controlled mating experiments to
test the hypothesis that post-copulatory sexual selection is dependent on a male’s perception of female parasite load in pipefish.
Our results provided no evidence for cryptic male choice based on perceived female parasite load. However, we found evidence
that eggs from larger females were more likely to result in viable offspring than eggs from smaller females and that the first
female to mate with a male transferred more eggs per copulation on average. Overall, our results show that potential for post-copulatory
sexual selection does exist in pipefish, but the male’s perception of female parasite load does not play a major role in this
process. 相似文献
3.
A comprehensive understanding of sexual selection requires knowledge of the traits and mechanisms responsible for increasing a male’s paternity share (proportion of progeny sired) relative to that of other males mating with the same female. In this study we manipulated by starvation the expression of traits that might influence male paternity share in Tribolium castaneum. We then conducted experiments to examine how male starvation affects male performance during sequential episodes of sexual selection from mating to progeny production, and investigated female control over specific stages by using live vs dead females. Comparison of starved vs fed males revealed that T. castaneum females have control over spermatophore transfer during mating, as live females rejected inseminations by starved (“low quality”) males. None of the measured male copulatory behaviors (leg-rubbing frequency, asymmetry, and percent of time spent rubbing) affected the probability of successful insemination, but the last two were positively associated with male paternity share. Spermatophore positioning within the female reproductive tract was not affected by male treatment (starved/fed), by female treatment (live/dead), or by male copulatory behaviors. Starvation, however, had a dramatic effect on male reproductive physiology, decreasing both accessory gland size and total number of sperms transferred (but not sperm viability in seminal vesicles). In addition, females who mated to starved males stored fewer sperms in their spermathecae, which, together with decreased ejaculate size, may explain the reduced paternity share of starved males compared to fed males. This study elucidates some cryptic mechanisms influencing male reproductive success and aids our understanding of trait evolution through sexual selection. 相似文献
4.
Paolo Galeotti Diego Rubolini Fabio Pupin Roberto Sacchi Mauro Fasola 《Behavioral ecology and sociobiology》2008,62(11):1739-1745
Asymmetry in traits of sexual relevance may impair copulation behaviour and sexual performance of males, ultimately resulting
in a fitness cost. Freshwater crayfish males use chelae, a sexually selected trait, to secure and position the female prior
to and during mating. Thus, a relatively large chelae asymmetry, resulting from accidental loss and regeneration of one cheliped
after autotomy, could have great consequences for male sexual behaviour. We studied copulatory behaviour and sperm expenditure
of males paired to a mated female in Austropotamobius italicus, a freshwater crayfish species where both male and female mate multiply and where last-mating males are able to actively
remove previously deposited sperm. We aimed at assessing whether male sperm removal and expenditure varied according to sperm
allocated by first-mating males, and according to copulation behaviour and phenotypic traits (carapace length, chelae length
and relative chelae asymmetry) of second-mating males. Second-mating males did not adjust their ejaculate size in relation
to first-mating male ejaculate, nor to the first-mating male’s sperm removed. Moreover, the amount of sperm removed by second-mating
males increased with increasing first-mating males ejaculate size, and first-mating male sperm remaining after removal did
not correlate with the original first-mating male ejaculate size. Interestingly, the amount of sperm removed by second-mating
males decreased with increasing relative chelae asymmetry, while increasing with male body size. However, second-mating (but
not first-mating) asymmetric-clawed males produced larger ejaculates than symmetric-clawed ones. Importantly, the proportion
of second-mating male sperm remaining after the two matings did not vary with relative chelae asymmetry nor with body size
of second-mating males. Thus, small, asymmetric-clawed crayfish males appear to adopt sperm allocation tactics that allow
them to fully compensate for their inferior sperm removal ability. 相似文献
5.
Determinants of paternity success in the spider Pholcus phalangioides (Pholcidae: Araneae): the role of male and female mating behaviour 总被引:1,自引:0,他引:1
In double mating experiments, we examined whether and to what extent various male and female behavioural traits influence
the course of mating and fertilization success in the cellar spider. In males, we focussed on pre-copulatory behaviour and
on the rhythmic twisting movements that the male performs with his pedipalps during copulation. In females, we investigated
remating decisions and the effect of female termination of copulation. Second males fertilized a high proportion of the eggs
(P
2: median 89%) despite much shorter second matings, with high variation in relative paternity success. The number of pedipalp
movements (PPMs) of either male was a better predictor of paternity than copulation duration. Our results suggest that in
second matings, PPMs help to remove sperm from previous males, whereas in first matings a high number of PPMs enhances fertilization
success, either due to numerical sperm competition or cryptic female choice. Furthermore, we found a negative male age effect
on paternity in second matings, implying that age-related deterioration of spermatozoa may promote variation in fertilization
success. Female receptivity decreased significantly in second matings; only 70% of the females remated. Females that accepted
a second copulation were found to terminate these much earlier and with higher probability than first matings. This suggests
that the intensity of conflict between the sexes is higher in second matings. Increased intensity of sexual conflict may be
responsible for stronger selection on male traits, as pre-copulatory behaviour and age only affected male copulatory performance
and paternity in second matings.
Electronic Publication 相似文献
6.
David Bierbach Claudia Kronmarck Carmen Hennige-Schulz Stefan Stadler Martin Plath 《Behavioral ecology and sociobiology》2011,65(9):1699-1707
Mate choice copying was mostly described as a strategy employed by females to assess the quality of potential mates, but also
males can copy other males’ mate choice. An open question in this context is whether and how copying males evaluate sperm
competition risk, as mating with a female that has already copulated with another male obviously sets the stage for intense
sperm competition (i.e., in species with internal fertilization). Using the livebearing Atlantic molly (Poecilia mexicana) as a model, we asked (a) whether males of that species indeed copy other males’ choices, and if they do so, (b) whether
copying males strategically adjust their behavior to sperm competition risk. We used an approach where focal males could first
choose to associate with a large or a small stimulus female. Mate choice tests were then repeated after an “observation phase”
during which either no model male was present (treatment 1, control) or the previously non-preferred female could be seen
associating (treatment 2) or physically interacting (treatment 3) with a model male. We found that, after the observation
phase, males spent considerably more time with the previously non-preferred female in treatment (2), i.e., they copied the
model male’s choice. This effect was much weaker during treatment (3) where sexual interactions between the model male and
the formerly non-preferred female were allowed. Males, therefore, seem to adjust their copying behavior strategically to the
perceived risk of sperm competition. 相似文献
7.
Shirley Raveh Dik Heg Vincent A. Viblanc David W. Coltman Jamieson C. Gorrell F. Stephen Dobson Adele Balmer Peter Neuhaus 《Behavioral ecology and sociobiology》2011,65(4):695-706
In polyandrous and polygynandrous species where females mate with multiple partners, males are expected to maximize their
fitness by exhibiting an array of reproductive behaviors to ensure fertilization success, such as competing for the best mating
order within a mating sequence, optimizing their investment in copulation, and mate guarding. Though there is genetic evidence
of a first-male precedence in siring success for many mammalian species, the causes of this effect are poorly understood.
We studied influences on first-male precedence in Columbian ground squirrels (Urocitellus columbianus). We found that the time a male spent consorting and mate guarding declined with his mating order (both the highest for the
first male to mate). Mate guarding by the first male significantly reduced, but did not exclude, the number of additional
males a female accepted. Later mating males reduced the time spent consorting, suggesting a perceived decreased chance of
fertilization success. Consortship and mate guarding durations were positively related to the male’s siring success and to
each other, suggesting that males adjusted these behaviors strategically to increase their chances of fertilization success.
Our results suggest that besides being the first male to consort, first-male sperm precedence is further enhanced through
longer mating bouts and by suppressing the chances and/or efforts of later mating males. 相似文献
8.
Females mating with multiple males may obtain direct benefits such as nuptial gifts or paternal care or indirect (i.e. genetic)
benefits resulting in higher-quality offspring. While direct benefits are easily identified, it is difficult to determine
indirect benefits, and it is hence largely unclear how they are obtained. This is particularly true in species with external
fertilisation, where females seem to have little control over fertilisation. In cichlids, most maternal mouthbrooders show
sequential multiple mating, where females visit several males for egg deposition. Genetic data revealed that multiple paternity
of eggs and young in the mouth of females is common, but behavioural data of female spawning decisions are missing. Here,
we test four hypotheses to explain female multiple mating in the maternally mouthbrooding cichlid, Ophthalmotilapia ventralis: (1) fertilisation insurance, (2) genetic bet-hedging, (3) female choice and (4) ‘sperm shopping’ (i.e. induction of sperm
competition resulting in sexually selected sperm). Detailed observations of spawning behaviour in the field combined with
histological analyses of the male reproductive organs suggest that fertilisation insurance, genetic bet-hedging and pre-mating
female choice are unlikely to explain the sequential female multiple mating in O. ventralis. Instead, cryptic female choice by sperm shopping, i.e. post-mating sexual selection, is most compatible with our data and
might be the major ultimate cause of multiple mating in females of this species and of mouthbrooding cichlids with maternal
care in general. Our study provides new insight into ultimate causes of sequential polyandry in species with external fertilisation,
as hitherto post-mating sexual selection by cryptic female choice has been assumed to be incompatible with external fertilisation
mechanisms except by components of the ovarian fluid. 相似文献
9.
Sperm competition or sperm selection: no evidence for female influence over paternity in yellow dung flies Scatophaga stercoraria 总被引:2,自引:0,他引:2
L. W. Simmons P. Stockley R. L. Jackson G. A. Parker 《Behavioral ecology and sociobiology》1996,38(3):199-206
Recent studies of non-random paternity have suggested that sperm selection by females may influence male fertilization success.
Here we argue that the problems originally encountered in partitioning variation in non-random mating between male competition
and female choice are even more pertinent to interpreting patterns of non-random paternity because of intense sperm competition
between males. We describe an experiment with the yellow dung fly, Scatophaga stercoraria, designed to partition variance in the proportion of offspring sired by the second male, P
2, between males and females, and to control for sperm competition. Large males were shown to have a higher P
2 than small males but P
2 was independent of the size of the female’s first mate. This result might suggest an absolute female preference for large
males via sperm selection. However, large males have a higher constant rate of sperm transfer and displacement. After controlling
for this effect of sperm competition, large males did not achieve higher paternity than small males. We argue that a knowledge
of the mechanism of sperm competition is essential so that male effects can be controlled before conclusions are made regarding
the influence of sperm selection by females in generating non-random paternity.
Received: 4 April 1995 / Accepted after revision: 17 October 1995 相似文献
10.
Sperm competition models on the evolution of sperm size assume associations with another sperm quality trait, sperm longevity. Sperm length can also provide an indication of possible mechanisms affecting motility and thus fertilization success. Despite their importance, however, detailed mechanisms of sperm competition at the gamete level are poorly understood. In simultaneously hermaphroditic land snails, sperm traits and cryptic female choice are assumed to be crucial in determining fertilization success. We examined the variation in sperm length and number among individuals from four natural populations of the land snail Arianta arbustorum, a species with multiple mating and long-term sperm storage. We also assessed variation in velocity, motility and longevity of sperm in snails from two of the four populations. Independent of shell size, sperm length differed among populations and, to a minor extent, even among individuals within populations. Mean sperm length of a snail was not correlated with the number of sperm delivered in a spermatophore. The mean sperm velocity (=VCL) did not differ between snails from two populations. However, VCL varied among snails. Percentage motility and longevity of sperm differed between snails from the two populations. No correlations were found between length, velocity, percentage motility and longevity of sperm. To conclude, individual snails differed in sperm quality, and this variation may partly explain the differential fertilization success between A. arbustorum snails. Moreover, our findings did not support the positive association between sperm length and longevity assumed by sperm competition models for internally fertilizing species. 相似文献
11.
Numbers of studies in externally fertilizing fish species provide evidence for an effect of ovarian fluid on sperm motility characteristics such as duration of forward mobility, velocity or percent motile sperm cells. Yet, because of variations among females in the quality of their ovarian fluid, such effects might differ between individuals. Additionally, ovarian fluid from different females could also be expected to affect each ejaculate differently, resulting in cryptic female choice. In this study on Artic charr (Salvelnius alpinus), sperm velocity from several males was measured in the diluted ovarian fluid of several females according to a fully balanced crossing design. This design allowed us to estimate variations among females in the effect of their ovarian fluid on the velocity of sperm from different males, and to detect variations among males in the ability of their sperm to swim in ovarian fluid. Sperm velocity was estimated by computer-assisted sperm analysis. Average velocity was found to vary among females, with some females having constantly higher velocity measurements in their ovarian fluid, and among males, indicating that some males had overall faster sperm in ovarian fluid than others. Moreover, variation in sperm velocity was shown to depend on individual female-male interactions. Our results document that females vary in the effect of their ovarian fluid on sperm velocity and that their ovarian fluid may stimulate sperm velocity according to individual characteristics of males. This latter result suggests a potential mechanism for cryptic female choice.
相似文献
Davnah UrbachEmail: Phone: +41-31-6313182Fax: +41-31-6314535 |
12.
The number of eggs fertilized by a male at any given copulation (fertilization success) is affected by a large number of factors. Male insemination and sperm competition success and various female structures and/or processes that bias paternity in favor of some males over others (cryptic female choice) are all likely to affect fertilization success. We suggest that more comprehensive measures of male fertilization success can increase our understanding of postcopulatory sexual selection. To improve our understanding of the importance of various sources of variance in male fertilization success, we conducted a series of experiments using flour beetles. Different wild-type strains were used in reciprocal double mating experiments, against a phenotypic marker strain. We assessed the relative effects of female genotype, male genotype and mating order on independent and inclusive measures of male defense ability ( P 1), male offense ability ( P 2), and female remating behavior. Female genotype influenced both P 1 and P 2, and male genotype interacted strongly with female genotype in its effect on P 2. We also documented an interaction between female and male genotypes in the effects of mating on female remating behavior, such that females tended to remate most rapidly when mated to males of their own genotype. It is clear from our experiments that cryptic female choice influences the pattern of fertilization success in flour beetles, and we suggest that cryptic female choice may often be an important component of postcopulatory sexual selection. Future investigations would benefit from studying the multiple components of variance in male fertilization success. 相似文献
13.
Many fishes are characterized by intense sperm competition between males that use alternative mating tactics. In externally
fertilizing fishes, males’ proximity to females during spawning can be an important determinant of fertilization success.
Here, we assess how mating tactic, body length, speed during streak spawns, and periphery cover affect males’ proximity to
females during sperm competition in the externally fertilizing bluegill (Lepomis macrochirus). Bluegill are characterized by three mating tactics referred to as parental, sneaker, and satellite. Parentals are territorial
and construct nests, while sneakers use a streaking behavior, and satellites use female mimicry to steal fertilizations from
parentals. We show that a small body length is important for sneakers but not for satellites to obtain a close position to
the female during spawning. Specifically, smaller sneakers obtain a closer position to females than larger sneakers in part
by positioning themselves closer on the periphery of a parental’s nest before streaking but show no difference in the speed
at which they streak. The amount of peripheral vegetation around a parental’s nest did not appear to affect proximity of sneakers
to females, and there was no relationship between the amount of peripheral vegetation and the frequency of intrusions by either
sneakers or satellites. Finally, parentals were farther from the female when a sneaker or satellite intruded than when they
spawned alone with the female. 相似文献
14.
Kevin J. Delaney J. Andrew Roberts George W. Uetz 《Behavioral ecology and sociobiology》2007,62(1):67-75
Male signaling behaviors are often studied in a single context but may serve multiple functions (e.g., in male–male competition
and female mate choice). We examined the issue of dual function male signals in a wolf spider species Schizocosa ocreata (Hentz) that displays the same species-specific signaling behaviors in both male–male and male–female contexts. These signaling
behaviors have been described as either aggression or courtship according to the context observed. We tested the possibility
of dual functions by comparing the relationship between behaviors and outcome of male–male contests (winner/loser) and male–female
mating encounters (mating success). Frequency, rate, and mean duration of signaling behaviors did not vary with outcome of
male–male contests, which appears instead to be based upon relative size and body mass. Winners of contests had significantly
greater body mass than losers, and greater mass relative to opponents was significantly associated with probability of winning.
Overall, signaling rates were much higher in male–female interactions than in male–male contests and were higher for males
that successfully mated than for those that did not mate. Mean duration of some male displays was also greater for males that
successfully mated. However, male size was not associated with probability of mating. Taken together, results suggest an intersexual
selection context for the current function of male signals in these wolf spiders and that increased display vigor is associated
with male mating success. 相似文献
15.
Joanna P. Y. Chan Pei Rong Lau Ai Jie Tham Daiqin Li 《Behavioral ecology and sociobiology》2008,62(5):639-646
In experiments that comprised of three phases (fight, choice, and mating) under “seen” and “unseen” conditions, we examined
the effects of the outcomes of male–male contests and female eavesdropping on female mate choice and male mating success in
the fighting spider, Thiania bhamoensis (Salticidae). The results revealed female eavesdropping on agonistic interactions. Females that had watched an aggressive
interaction showed no distinctive preference for the winner over the loser, but they preferred the loser when they had not
observed a fight. Winners, however, achieved a greater mating success than did losers during the mating phase. Gaining access
to females was based on the insistence of the winners in courtship in terms of the number of quivers, rather than on the fighting
behavior of the males. Hence, the outcome of male–male contests may not be an important determinant of a male’s mating success
in T. bhamoensis. Instead, courtship display plays an important role in determining the success of male mating in this species. This study
also suggests that female mate preference may not be a good indicator of eventual female mate choice and male mating success.
Thus, a causal relationship between female mate preference and male mating success cannot be inferred.
Joanna P. Y. Chan, Pei Rong Lau, and Ai Jie Tham contributed equally. 相似文献
16.
While studies on a wide diversity of organisms have demonstrated the importance of female behavior during matings, in crustacean studies, a strong bias towards male mating behavior prevails. Reproductively mature rock shrimp (Rhynchocinetes typus) exist as several ontogenetic stages that differ in their morphological and physiological capacities. In natural populations, the majority of males are in early ontogenetic stages (termed typus), many are in intermediate stages (intermedius), and few are in the terminal molt stage (robustus). Dominant robustus males, which have already demonstrated their biological fitness by surviving to this stage, have previously been shown to have a higher potential than subordinate typus males to defend receptive females against other males, and fertilize the entire clutch of a female. While females should thus show a preference for robustus males, they nevertheless frequently receive sperm from typus males. These observations suggested that females might have mechanisms to discriminate against sperm from subordinate males. In laboratory experiments, we observed that females avoided being seized by typus males for longer time periods in the absence of robustus males than in their presence. Following seizure, females that were initially held by typus males, required more time to initiate spawning than those held by robustus males. Many typus males transferred spermatophores to females before these started to spawn while robustus males waited until females began to spawn before they transferred spermatophores. Females manipulated spermatophores received from typus males for long time periods (minutes), but not those they received from robustus males. By accepting sperm from subordinate typus males, females may avoid further harassment (convenience polyandry), but they subsequently may discriminate against these subordinate males by delaying spawning and removing their sperm. These observations suggest that female behavior influences the outcome of matings, favoring fertilization of eggs by sperm from dominant males. Convenience polyandry and cryptic female choice may be common in other crustaceans as well.Electronic Supplementary Material Supplementary material is available in the online version of this article at .Communicated by T. Czeschlik 相似文献
17.
Parker's seminal work brought attention to the possibility of postmating sexual selection by non-random fertilization success.
Mechanisms for these processes are still only partly understood and there is clearly a need for more studies of intraspecific
variation in sperm precedence. Here, we report results from an experimental study of the variation in fertilization success
between males of the water strider Gerris lacustris. Genital morphology, male body size, and copulation duration were examined as possible correlates of paternity. The significance
of guarding duration was also analysed. Only male genital morphology was correlated to fertilization success. This is one
of the first studies showing a relationship between male genital traits and fertilization success, supporting the view that
sexual selection may be responsible for the rapid and divergent evolution of genital structures in animals with internal fertilization.
The fertilization success of last males varied considerably after double matings with a short mating interval (10 min). Last-male
priority ranged from 0 to 100% and usually one of the males involved fertilized almost all the eggs. After double matings
with a short mating interval, the proportion of eggs fertilized by the last male averaged 0.68 and was greater than 0.5. In
contrast, the average fertilization success was biased towards the first male when the matings were more spread out over time
(24 h). These results do not support earlier suggestions of a widespread last-male sperm priority in water striders.
Received: 28 July 1998 / Received in revised form: 15 March 1999 / Accepted: 28 March 1999 相似文献
18.
Merja Otronen 《Behavioral ecology and sociobiology》1998,42(3):185-191
The significance of male asymmetry in postcopulatory sexual selection was studied in the fly Dryomyza anilis by examining whether male asymmetry is related to fertilization success. The traits measured were wing length, tibia length
and the length of small and large claspers. The male claspers are situated at the tip of the abdomen, functional pair of claspers
consists of a large and a small clasper on the same side of the body. These claspers are used to tap the female abdomen after
sperm transfer, which has been shown to increase fertilization success for the mating male. Fertilization success was negatively
related to the fluctuating asymmetry of wing length, suggesting either female preference for more symmetrical males or a relationship
between male asymmetry and intrasexual selection which was reflected in mating performance. Fertilization success was also
related to the length of small claspers, decreasing with increasing length of the claspers. In addition, males with asymmetrical
small claspers enjoyed higher fertilization success than symmetrical ones. This study shows that fluctuating asymmetry in
wing length is an important fitness trait in postcopulatory sexual selection. Since male tapping affects sperm distribution
in the female's sperm storage organs, the higher fertilization success of males with asymmetrical small claspers could have
a functional relationship with the asymmetrical position of female sperm storage organs.
Received: 6 March 1997 / Accepted after revision: 8 November 1997 相似文献
19.
Bushcricket males of Poecilimon zimmeri transfer large and protein-rich spermatophores during mating, which females directly ingest. There is correlational evidence
that heavier males transfer larger nuptial gifts. In no-choice mating trials, females mated randomly with respect to male’s
body weight. In contrast, in two-choice mating trials, female bushcrickets exhibit clear choice for the heavier male. This
heavier male advantage was also found in pre-mating choice during phonotaxis. With manipulated mute males, females mated at
random with regard to body weight of the competitors. The number of physical encounters between a female and males was low
in all tests with a single male (no choice) and greater in choice-tests with two competing males. The latencies to mate also
differed significantly between treatments. The time mating pairs spent in precopula was short in experiments where the males
could hear rivals and significantly longer in all other tests using either a single male or mute males. Thus, acoustic signalling
in male bushcrickets seems to signal male body weight. A preference for heavier males may reflect a female’s preference for
a larger spermatophore and therefore a greater direct benefit. 相似文献
20.
Michael J. Young Leigh W. Simmons Jonathan P. Evans 《Behavioral ecology and sociobiology》2010,64(6):915-925
Sexual selection can act through female choice and male–male competition. Although both processes can act simultaneously,
they are typically studied independently. Here, we adopt a more integrated approach to studying sexual selection by incorporating
measures of both processes using the western rainbowfish Melanotaenia australis, a freshwater fish endemic to northwestern Australia. We assessed male–male competition and female choice separately while
measuring the performance of individual males under both processes and used paternity analyses to estimate male reproductive
success. We then related the performance of males during each of these stages to their phenotype, which was described using
linear measures of size and color pattern traits, and spectrographic measures of the reflectance of color patches. We found
that female choice favored relatively large males and that these preferences were consistent within individual females and
repeatable between different females. Larger males were also more dominant in the competition trials and sired the majority
of offspring produced when females spawned. There was little evidence to suggest that sexual selection acted on male color
patterns either via female choice or male contest competition or during subsequent post-mating episodes of sexual selection.
We conclude, therefore, that male–male competition and female choice act concordantly to favor relatively large males and
that these patterns of mating success are reflected during post-mating episodes of sexual selection. 相似文献