Differential survival of allosperm by location within the female storage organ of the snail Cornu aspersum

2008 ◽  
Vol 86 (11) ◽  
pp. 1244-1251 ◽  
Author(s):  
Ronald Chase ◽  
Emily Darbyson
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Complex Structure ◽  
Sperm Storage ◽  
Storage Organ ◽  
Differential Survival ◽  
Cornu Aspersum ◽  
The Mean ◽  
Epithelial Wall

The sperm storage organ of terrestrial gastropod molluscs is implicated in sexual selection because it has a complex structure and it functions in a context of intense sperm competition. Received sperm are stored in spermathecal tubules. In our sample using the brown garden snail ( Cornu aspersum (Müller, 1774)) (n = 58), the mean number of tubules per animal was 16, with lengths ranging from ≤40 to 2480 μm. A hereditary influence on tubule number was indicated by clutch-dependent variations. From histological sections, we counted the spermatozoa that were present in the tubules of ex-virgin snails 1, 2, 4, and 8 weeks after mating (n = 40). Sperm were distributed, on average, across 75% of the tubules in individual snails, thus contradicting one proposed mechanism for cryptic female choice. The total number of sperm declined 66% over 8 weeks, with the largest losses incurred by sperm in the lumens of the tubules and sperm gathered in clusters. By contrast, in the same period, the numbers of sperm that were in contact with the walls of the tubules remained relatively stable. These data imply that sperm survive best when attached to the epithelial wall, either because they derive nutrition from the epithelium or because they use the epithelium as an anchor.

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.

scholarly journals Gamete-mediated mate choice: towards a more inclusive view of sexual selection

2018 ◽  
Vol 285 (1883) ◽  
pp. 20180836 ◽  
Author(s):  
Jukka Kekäläinen ◽  
Jonathan P. Evans
Keyword(s):  
Sexual Selection ◽  
Mate Choice ◽  
Sperm Competition ◽  
Female Choice ◽  
Mating Systems ◽  
Molecular Level ◽  
Evolutionary Significance ◽  
Random Interactions ◽  
Physiological Processes ◽  
The Everyday

‘Sperm competition’—where ejaculates from two or more males compete for fertilization—and ‘cryptic female choice’—where females bias this contest to suit their reproductive interests—are now part of the everyday lexicon of sexual selection. Yet the physiological processes that underlie these post-ejaculatory episodes of sexual selection remain largely enigmatic. In this review, we focus on a range of post-ejaculatory cellular- and molecular-level processes, known to be fundamental for fertilization across most (if not all) sexually reproducing species, and point to their putative role in facilitating sexual selection at the level of the cells and gametes, called ‘gamete-mediated mate choice’ (GMMC). In this way, we collate accumulated evidence for GMMC across different mating systems, and emphasize the evolutionary significance of such non-random interactions among gametes. Our overall aim in this review is to build a more inclusive view of sexual selection by showing that mate choice often acts in more nuanced ways than has traditionally been assumed. We also aim to bridge the conceptual divide between proximal mechanisms of reproduction, and adaptive explanations for patterns of non-random sperm–egg interactions that are emerging across an increasingly diverse array of taxa.

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 Disposable penis and its replenishment in a simultaneous hermaphrodite

2013 ◽  
Vol 9 (2) ◽  
pp. 20121150 ◽  
Author(s):  
Ayami Sekizawa ◽  
Satoko Seki ◽  
Masakazu Tokuzato ◽  
Sakiko Shiga ◽  
Yasuhiro Nakashima
Keyword(s):  
Sexual Selection ◽  
Outer Surface ◽  
Mating Behaviour ◽  
Sperm Storage ◽  
Simultaneous Hermaphrodite ◽  
Storage Organ ◽  
Simultaneous Hermaphrodites

Although it is often thought that sexual selection is weaker in simultaneous hermaphrodites than in gonochorists, some simultaneous hermaphrodites exhibit bizarre mating behaviour. In the simultaneously hermaphroditic nudibranch Chromodoris reticulata , we found a peculiar mating behaviour, wherein the nudibranch autotomized its penis after each copulation and was able to copulate again within 24 h. To have sufficient length to be replenished for three copulations, the penis is compressed and spiralled internally. No other animal is known to repeatedly copulate using such ‘disposable penes’. Entangled sperm masses were observed on the outer surface of the autotomized penis, which is equipped with many backward-pointed spines. There is a possibility that the nudibranch removes sperm already stored in a mating partner's sperm storage organ(s).

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 Multiple sperm storage organs facilitate female control of paternity

2005 ◽  
Vol 272 (1568) ◽  
pp. 1139-1144 ◽  
Author(s):  
Lindsay S.E Snow ◽  
Maydianne C.B Andrade
Keyword(s):  
Sperm Storage ◽  
Conclusive Evidence ◽  
Sperm Precedence ◽  
Storage Organ ◽  
Use Patterns ◽  
Storage Organs ◽  
The Mean ◽  
Female Control ◽  
Latrodectus Hasselti ◽  
Normally Distributed

It has been proposed that multiple sperm storage organs (spermathecae) could allow polyandrous females to control paternity. There is little conclusive evidence for this since insemination of individual spermathecae is generally not experimentally manipulable. Here, we examined sperm use patterns in the Australian redback spider ( Latrodectus hasselti ), which has paired, independent spermathecae. We assessed paternity when two rivals were forced to inseminate a single storage organ or opposite storage organs. When males inseminated a single spermatheca, mean paternity of the female's first mate was 79.8% (median 89.4%), and 38% of first mates achieved 100% paternity. In contrast, when males inseminated opposite organs, the mean paternity of the first mate was 49.3% (median 49.9%), only 10% of males achieved complete precedence, and paternity was normally distributed, suggesting sperm mixing. Males responded to this difference by avoiding previously inseminated female reproductive tracts. Complete sperm precedence can only be achieved if females permit males to copulate with both reproductive tracts. Females often cannibalize smaller males during their first copulation, thus limiting their paternity to 50%. These data show that multiple sperm storage organs can increase female control of paternity.

scholarly journals Evidence of sperm removal behaviour in an externally fertilizing species and compensatory behaviour for the risk of self-sperm removal

2020 ◽  
Vol 287 (1937) ◽  
pp. 20202004
Author(s):  
Takeshi Takegaki ◽  
Ayako Nakanishi ◽  
Yosuke Kanatani ◽  
Shoma Kawase ◽  
Masa-aki Yoshida ◽  
...  
Keyword(s):  
Sperm Competition ◽  
Marine Fish ◽  
Sperm Storage ◽  
Storage Organ ◽  
Injection Treatment ◽  
Sperm Release ◽  
Competition Avoidance ◽  
Focal Male ◽  
First Time ◽  
Fanning Behaviour

The removal of rival sperm from a female's sperm storage organ acts as a strong sperm competition avoidance mechanism, which has been reported only in internally fertilizing species and not at all in externally fertilizing species. This study demonstrated for the first time that nest-holding males of Bathygobius fuscus , an externally fertilizing marine fish, remove the sperm of rival sneaker males from the spawning nest by exhibiting tail-fanning behaviour within the nest. Males showed tail-fanning behaviour when semen was artificially injected into the nest but not when seawater was injected, and in open nests this behaviour resulted in higher paternity rates for the focal male. The sperm removal behaviour entails the risk of removing their own sperm; therefore, additional sperm release behaviour is likely necessary to benefit from the sperm removal effect. Consistent with this, males increased post-fanning sperm release behaviour more in the semen than in the seawater injection treatment. Moreover, males who had removed sperm for a longer time spent more time releasing sperm after the removal, suggesting that the additional sperm release behaviour compensated for the loss of their own sperm. These results suggest that sperm removal behaviour is not restricted to internally fertilizing organisms and deserves further investigation in this and other species.

scholarly journals Reproductive consequences of an extra long-term sperm storage organ

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Akashdeep Dhillon ◽  
Tabashir Chowdhury ◽  
Yolanda E. Morbey ◽  
Amanda J. Moehring
Keyword(s):  
Reproductive Success ◽  
Candidate Gene ◽  
Sperm Competition ◽  
Sperm Storage ◽  
Female Fitness ◽  
Storage Organ ◽  
Empirical Tests ◽  
Reproductive Consequences

Abstract Background Sperm storage plays a key role in the reproductive success of many sexually-reproducing organisms, and the capacity of long-term sperm storage varies across species. While there are theoretical explanations for why such variation exists, to date there are no controlled empirical tests of the reproductive consequences of additional long-term sperm storage. While Dipterans ancestrally have three long-term sperm organs, known as the spermathecae, Drosophila contain only two. Results We identified a candidate gene, which we call spermathreecae (sp3), in which a disruption cause the development of three functional spermathecae rather than the usual two in Drosophila. We used this disruption to test the reproductive consequences of having an additional long-term sperm storage organ. Compared to females with two spermathecae, females with three spermathecae store a greater total number of sperm and can produce offspring a greater length of time. However, they did not produce a greater total number of offspring. Conclusions Thus, additional long-term sperm storage in insects may increase female fitness through extending the range of conditions where she produces offspring, or through increasing the quality of offspring via enhanced local sperm competition at fertilization.

Sexual Selection by Sperm Competition in Birds: Male-Male Competition or Female Choice?

1994 ◽  
Vol 25 (3) ◽  
pp. 244 ◽  
Author(s):  
Jan T. Lifjeld ◽  
Peter O. Dunn ◽  
David F. Westneat
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Male Competition

Anatomical Studies on the sperm storage organ of Pati and Chara-Chemballi Ducks

2017 ◽  
Author(s):  
A. Deka ◽  
K. Sarma ◽  
S. Sarma ◽  
J. Goswami ◽  
J. D. Mahanta ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Positive Reaction ◽  
Anatomical Study ◽  
Goblet Cells ◽  
Sperm Storage ◽  
Storage Organ ◽  
Anatomical Studies ◽  
Length Width ◽  
The Mean

The present investigation was conducted on the comparative anatomical study of vagina (sperm storage organ) of Pati and Chara-Chemballi ducks during laying periods. The vagina was collected immediately after death and anatomical studies were made on it. The vagina was a narrow muscular tube, sharply curved and was tightly bound by ligament. The length, width thickness and weight of vagina of Chara-Chemballi ducks were significantly (p>0.01) higher than Pati duck. The lining epithelium consisted of pseudostratified columnar epithelial cells with few goblet cells. The mean height of lamina epithelialis mucosae of vagina of the present study was significantly (p>0.01) higher in Chara-Chemballi duck (26.508±0.298 µm) than Pati duck (23.058±0.330 µm). A weak PAS positive reaction was noticed in the lining epithelium of vagina of Pati and Chara-Chembali ducks.

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