scholarly journals Post-copulatory opportunities for sperm competition and cryptic female choice provide no offspring fitness benefits in externally fertilizing salmon

2016 ◽  
Vol 3 (3) ◽  
pp. 150709 ◽  
Author(s):  
Alyson J. Lumley ◽  
Sian E. Diamond ◽  
Sigurd Einum ◽  
Sarah E. Yeates ◽  
Danielle Peruffo ◽  
...  
Keyword(s):  
Sperm Competition ◽  
Female Choice ◽  
Life Stage ◽  
Cryptic Female Choice ◽  
Growth And Survival ◽  
Offspring Fitness ◽  
Natural Streams ◽  
Fitness Benefits ◽  
Similar Survival

There is increasing evidence that females can somehow improve their offspring fitness by mating with multiple males, but we understand little about the exact stage(s) at which such benefits are gained. Here, we measure whether offspring fitness is influenced by mechanisms operating solely between sperm and egg. Using externally fertilizing and polyandrous Atlantic salmon ( Salmo salar ), we employed split-clutch and split-ejaculate in vitro fertilization experiments to generate offspring using designs that either denied or applied opportunities for sperm competition and cryptic female choice. Following fertilizations, we measured 140 days of offspring fitness after hatch, through growth and survival in hatchery and near-natural conditions. Despite an average composite mortality of 61%, offspring fitness at every life stage was near-identical between groups fertilized under the absence versus presence of opportunities for sperm competition and cryptic female choice. Of the 21 551 and 21 771 eggs from 24 females fertilized under monandrous versus polyandrous conditions, 68% versus 67.8% survived to the 100-day juvenile stage; sub-samples showed similar hatching success (73.1% versus 74.3%), had similar survival over 40 days in near-natural streams (57.3% versus 56.2%) and grew at similar rates throughout. We therefore found no evidence that gamete-specific interactions allow offspring fitness benefits when polyandrous fertilization conditions provide opportunities for sperm competition and cryptic female choice.

Post-Copulatory Sexual Selection

2021 ◽  
Author(s):  
Patricia L.R. Brennan ◽  
Dara N. Orbach
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Reproductive Tract ◽  
Seminal Fluid ◽  
Fertilization Success ◽  
Female Reproductive Tract ◽  
Cryptic Female Choice ◽  
Trade Offs ◽  
Morphological Criteria

The field of post-copulatory sexual selection investigates how female and male adaptations have evolved to influence the fertilization of eggs while optimizing fitness during and after copulation, when females mate with multiple males. When females are polyandrous (one female mates with multiple males), they may optimize their mating rate and control the outcome of mating interactions to acquire direct and indirect benefits. Polyandry may also favor the evolution of male traits that offer an advantage in post-copulatory male-male sperm competition. Sperm competition occurs when the sperm, seminal fluid, and/or genitalia of one male directly impacts the outcome of fertilization success of a rival male. When a female mates with multiple males, she may use information from a number of traits to choose who will sire her offspring. This cryptic female choice (CFC) to bias paternity can be based on behavioral, physiological, and morphological criteria (e.g., copulatory courtship, volume and/or composition of seminal fluid, shape of grasping appendages). Because male fitness interests are rarely perfectly aligned with female fitness interests, sexual conflict over mating and fertilization commonly occur during copulatory and post-copulatory interactions. Post-copulatory interactions inherently involve close associations between female and male reproductive characteristics, which in many species potentially include sperm storage and sperm movement inside the female reproductive tract, and highlight the intricate coevolution between the sexes. This coevolution is also common in genital morphology. The great diversity of genitalia among species is attributed to sexual selection. The evolution of genital attributes that allow females to maintain reproductive autonomy over paternity via cryptic female choice or that prevent male manipulation and sexual control via sexually antagonistic coevolution have been well documented. Additionally, cases where genitalia evolve through intrasexual competition are well known. Another important area of study in post-copulatory sexual selection is the examination of trade-offs between investments in pre-copulatory and post-copulatory traits, since organisms have limited energetic resources to allocate to reproduction, and securing both mating and fertilization is essential for reproductive success.

scholarly journals Male–female relatedness at specific SNP-linkage groups influences cryptic female choice in Chinook salmon ( Oncorhynchus tshawytscha )

2017 ◽  
Vol 284 (1859) ◽  
pp. 20170853 ◽  
Author(s):  
Cornelia Geßner ◽  
Sheri L. Johnson ◽  
Paul Fisher ◽  
Shannon Clarke ◽  
Kim Rutherford ◽  
...  
Keyword(s):  
Female Choice ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Fertilization Success ◽  
Cryptic Female Choice ◽  
Linkage Groups ◽  
Sperm Velocity ◽  
Ovarian Fluid ◽  
The Impact

In a range of taxa, the relatedness between mates influences both pre- and post-mating processes of sexual selection. However, relatively little is known about the genetic loci facilitating such a bias, with the exception of the major histocompatibility complex. Here, we performed tightly controlled replicated in vitro fertilization trials to explore the impact of relatedness on two possible mechanisms of cryptic female choice (CFC) in Chinook salmon ( Oncorhynchus tshawytscha ). We tested (i) whether relatedness of mates, assessed using 682 single nucleotide polymorphisms (SNPs) on 29 SNP-linkage groups (LGs), biases a male's sperm velocity in ovarian fluid (a parameter previously shown to predict male fertilization success), and (ii) whether relatedness of mates governs fertilization success via other mechanisms, probably via sperm–egg interactions. We found that relatedness on three LGs explained the variation in sperm velocity, and relatedness on two LGs explained fertilization success, which might indicate the presence of genes important in sperm–ovarian fluid and sperm–egg interactions in these genomic regions. Mapping of the SNPs on these LGs to the rainbow trout genome revealed two genes that affect fertility in humans and represent candidate genes for further studies. Our results thereby provide a novel contribution to the understanding of the mechanism of CFC.

scholarly journals Can cryptic female choice prevent invasive hybridization in external fertilizing fish?

2021 ◽  
Author(s):  
Tyler H. Lantiegne ◽  
Craig F. Purchase
Keyword(s):  
Sperm Competition ◽  
Female Choice ◽  
North American ◽  
Native Species ◽  
Salmo Trutta ◽  
Swimming Performance ◽  
Cryptic Female Choice ◽  
Swimming Velocity ◽  
Reproductive Tactics ◽  
The North

Polyandrous mating systems result in females mating with multiple males. This includes the potential for unintended matings and subsequent sperm competition with hybridizing species, especially in the presence of alternative reproductive tactics (sneaker males). Cryptic female choice allows females to bias paternity towards preferred males under sperm competition and may include conspecific sperm preference when under hybridization threat. The potential becomes particularly important in context of invasive species that can novelly hybridize with natives. We provide the first examination of conspecific sperm preference in a system of three species with potential to hybridize: North American native Atlantic salmon (Salmo salar) and brook char (Salvelinus fontinalis), and invasive brown trout (Salmo trutta) from Europe. Using naturalized populations on the island of Newfoundland, we measured changes in sperm swimming performance, a known predictor of paternity, to determine the degree of upregulation to female cues related to conspecific sperm preference. Compared to water alone, female ovarian fluid in general had a pronounced effect and upregulated sperm motility (mean 53%) and swimming velocity (mean 30%). However, patterns in the degree of upregulation suggest there is no conspecific sperm preference in the North American populations. Furthermore, female cues from both native species tended to boost the sperm of invasive males more than their own. We conclude that cryptic female choice is too weak in this system to prevent invasive hybridization and is likely insufficient to promote or maintain reproductive isolation between the native species.

5. Sexual selection after mating

2018 ◽  
pp. 69-87
Author(s):  
Leigh W. Simmons
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Reproductive Tract ◽  
Multiple Mating ◽  
Reproductive Traits ◽  
Cryptic Female Choice ◽  
Mate Acquisition ◽  
Evolutionary Consequences

Darwin viewed sexual selection as a process that ended with mate acquisition, assuming that females are fundamentally monogamous, mating with just one male. ‘Sexual selection after mating’, however, shows this assumption to be false. Sexual selection continues long after the physical act of mating is over, as sperm compete inside a female’s reproductive tract and females bias the paternity of their young by selectively using sperm from particular males. Multiple mating by females has turned out to be ubiquitous across animal taxa. The far-reaching evolutionary consequences of sperm competition and cryptic female choice for the evolution of reproductive traits are examined, from the gametes themselves to the adult organisms producing them.

scholarly journals Cryptic female choice enhances fertilization success and embryo survival in chinook salmon

2016 ◽  
Vol 283 (1827) ◽  
pp. 20160001 ◽  
Author(s):  
Patrice Rosengrave ◽  
Robert Montgomerie ◽  
Neil Gemmell
Keyword(s):  
Female Choice ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Genetic Relatedness ◽  
Fertilization Success ◽  
Cryptic Female Choice ◽  
Embryo Survival ◽  
Sperm Swimming Speed ◽  
Fertilization Experiments

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon ( Oncorhynchus tshawytscha ): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality) and female–male genetic relatedness on sperm behaviour and male fertilization success when there is sperm competition in the presence of that OF. To do this, we conducted a series of in vitro competitive fertilization experiments and found that, when ejaculates from two males are competing for access to a single female's unfertilized eggs, fertilization success was significantly biased towards the male whose sperm swam fastest in the female's OF. Embryo survival—a measure of fitness—was also positively correlated with both sperm swimming speed in OF and male MLH, providing novel evidence that cryptic female choice is adaptive for the female, enhancing the early survival of her offspring and potentially influencing her fitness.

Sperm competition: evolutionary causes and consequences

1995 ◽  
Vol 7 (4) ◽  
pp. 755 ◽  
Author(s):  
TR Birkhead
Keyword(s):  
Sperm Competition ◽  
Zebra Finch ◽  
Female Choice ◽  
Temporal Pattern ◽  
Cryptic Female Choice ◽  
Optimal Time ◽  
Optimal Timing ◽  
Sperm Precedence ◽  
Male And Female ◽  
Ejaculate Size

The interaction between functional and mechanistic approaches to sperm competition and between male and female perspectives are described and illustrated by a study of the zebra finch, Taeniopygia guttata. Sperm competition experiments in the laboratory show that last male sperm precedence occurs (as it does in many other taxa) although the mechanism is unknown (as in most other taxa). Empirically-derived values were used to construct a mathematical model of sperm competition in the zebra finch. The model indicates that precedence occurs as a consequence of: (i) the temporal pattern of pair copulations; (ii) the rate at which sperm are lost from the female tract; and (iii) more sperm being transferred during extra-pair copulations than during pair copulations. The latter effect is a consequence of males seeking extra-pair copulations after their own pair copulation period has ended. The effect of sperm numbers on the pattern of sperm precedence may be further increased by: (i) extra-pair males increasing ejaculate size (sperm numbers) (for which there is no evidence); (ii) extra-pair males being of a better quality and transferring more sperm or better quality sperm (for which there is some evidence); and (iii) cryptic female choice. Females eject over 99% of sperm following insemination; if they eject fewer sperm from males chosen as extra-pair copulation partners, the potential for cryptic female choice is considerable. However, this is still being investigated. The model also predicts the optimal time for an extra-pair copulation to occur (from either a male or female perspective). A comparison between the predicted and observed pattern suggests that the optimal timing of extra-pair copulations is constrained in both sexes.

scholarly journals Female × male and male × male interactions have limited influence on competitive fertilization inDrosophila melanogaster

2019 ◽  
Author(s):  
Stefan Lüpold ◽  
Jonathan Bradley Reil ◽  
Mollie K. Manier ◽  
Valérian Zeender ◽  
John M. Belote ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Sperm Storage ◽  
Sperm Transfer ◽  
Cryptic Female Choice ◽  
Complex Interactions ◽  
Sexually Selected Traits ◽  
Selected Traits ◽  
Reproductive Events

AbstractHow males and females contribute to joint reproductive success has been a long-standing question in sexual selection. Under postcopulatory sexual selection (PSS), paternity success is predicted to derive from complex interactions among females engaging in cryptic female choice and males engaging in sperm competition. Such interactions have been identified as potential sources of genetic variation in sexually selected traits but are also expected to inhibit trait diversification. To date, studies of interactions between females and competing males have focused almost exclusively on genotypes and not phenotypic variation in sexually selected traits. Here, we characterize within- and between-sex interactions inDrosophila melanogasterusing isogenic lines with heritable variation in both male and female traits known to influence competitive fertilization. We found surprisingly few genotypic interaction effects on various stages of PSS such as female remating interval, copulation duration, sperm transfer, or sperm storage. Only the timing of female sperm ejection depended on female × male genotypic interactions. By contrast, several reproductive events, including sperm transfer, female sperm ejection and sperm storage, were explained by two- and three-way interactions among sex-specific phenotypes. We also documented complex interactions between the lengths of competing males’ sperm and the female seminal receptacle, which are known to have experienced rapid female-male co-diversification. Our results highlight the non-independence of sperm competition and cryptic female choice and demonstrate that complex interactions between the sexes do not limit the ability of multivariate systems to respond to directional sexual selection.Significance statementFor species with internal fertilization and female promiscuity, postcopulatory sexual selection (PSS) is believed to depend, in part, on complex interactions between rival males and between the sexes. Although little investigated, clarifying such interactions is critical as they may limit the efficacy of PSS in the diversification of reproductive traits (e.g., ejaculate biochemistry and sperm, genitalia and female reproductive tract morphology). Here, we resolve how sex-specific traits and their interactions contribute to key reproductive events and outcomes related to competitive fertilization success, including traits known to have experienced rapid diversification. Our results provide novel insights into the operation and complexity of PSS and demonstrate that the processes of sperm competition and cryptic female choice are not independent selective forces.

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