Sperm transfer and storage in relation to sperm competition in Callosobruchus maculatus

1994 ◽  
Vol 35 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Paul Eady
Keyword(s):  
Sperm Competition ◽  
Callosobruchus Maculatus ◽  
Sperm Transfer ◽  
And Storage

scholarly journals Functional morphology of immature mating in a widow spider

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lenka Sentenská ◽  
Aileen Neumann ◽  
Yael Lubin ◽  
Gabriele Uhl
Keyword(s):  
Sperm Competition ◽  
Storage Conditions ◽  
Sperm Storage ◽  
Sperm Transfer ◽  
Costs And Benefits ◽  
Micro Computed Tomography ◽  
Mating Tactics ◽  
Adult Females ◽  
Storage Organs ◽  
Widow Spider

Abstract Background Mating generally occurs after individuals reach adulthood. In many arthropods including spiders, the adult stage is marked by a final moult after which the genitalia are fully developed and functional. In several widow spider species (genus Latrodectus), however, immature females may mate a few days before they moult to adulthood, i.e. in their late-subadult stage. While the “adult” mating typically results in cannibalism, males survive the “immature” mating. During both “immature” and “adult” matings, males leave parts of their paired copulatory organs within female genitalia, which may act as mating plugs. To study potential costs and benefits of the two mating tactics, we investigated female genital morphology of the brown widow spider, L. geometricus. Light microscopy, histology and micro-computed tomography of early-subadult, late-subadult and adult females were conducted to determine the overall pattern of genital maturation. We compared genitalia of mated late-subadult and adult females to reveal potential differences in the genitalic details that might indicate differential success in sperm transfer and different environments for sperm storage and sperm competition. Results We found that the paired sperm storage organs (spermathecae) and copulatory ducts are developed already in late-subadult females and host sperm after immature mating. However, the thickness of the spermathecal cuticle and the staining of the secretions inside differ significantly between the late-subadult and adult females. In late-subadult females mating plugs were found with higher probability in both spermathecae compared to adult females. Conclusions Sperm transfer in matings with late-subadult females follows the same route as in matings with adult females. The observed differences in the secretions inside the spermathecae of adult and late-subadult females likely reflect different storage conditions for the transferred sperm which may lead to a disadvantage under sperm competition if the subadult female later re-mates with another male. However, since males mating with late-subadult females typically transfer sperm to both spermathecae they might benefit from numerical sperm competition as well as from monopolizing access to the female sperm storage organs. The assessment of re-mating probability and relative paternity will clarify the costs and benefits of the two mating tactics in light of these findings.

scholarly journals Pattern of sperm transfer in redback spiders: implications for sperm competition and male sacrifice

2004 ◽  
Vol 15 (5) ◽  
pp. 785-792 ◽  
Author(s):  
Lindsay S. E. Snow ◽  
Maydianne C. B. Andrade
Keyword(s):  
Sperm Competition ◽  
Sperm Transfer

scholarly journals SPERM TRANSFER AND STORAGE IN THE BROODING BIVALVEMYSELLA TUMIDA

1985 ◽  
Vol 169 (3) ◽  
pp. 602-614 ◽  
Author(s):  
DIARMAID Ó FOIGHIL
Keyword(s):  
Sperm Transfer ◽  
And Storage

scholarly journals No support for the sexy-sperm hypothesis in the seed beetle: sons of monandrous females fare better in post-copulatory competition

2018 ◽  
Author(s):  
Kristin A. Hook
Keyword(s):  
Sperm Competition ◽  
Genetic Architecture ◽  
Callosobruchus Maculatus ◽  
Empirical Work ◽  
Male Mating ◽  
Genetic Constraints ◽  
Seed Beetle ◽  
Indirect Fitness ◽  
Post Hoc ◽  
Sexy Sperm

ABSTRACTThe sexy-sperm hypothesis posits that polyandrous females derive an indirect fitness benefit from multi-male mating because they increase the probability their eggs are fertilized by males whose sperm have high fertilizing efficiency, which is assumed to be heritable and conferred on their sons. However, whether this process occurs is contentious because father-to-son heritability may be constrained by the genetic architecture underlying traits important in sperm competition within certain species. Previous empirical work has revealed such genetic constraints in the seed beetle,Callosobruchus maculatus, a model system in sperm competition studies in which female multi-male mating is ubiquitous. Using the seed beetle, I tested a critical prediction of the sexy-sperm hypothesis that polyandrous females produce sons that are on average more successful under sperm competition than sons from monandrous females. Contrary to the prediction of the sexy-sperm hypothesis, I found that sons from monandrous females had significantly higher relative paternity in competitive double matings. Moreover, post-hoc analyses revealed that these sons produced significantly larger ejaculates when second to mate, despite being smaller. This study is the first to provide empirical evidence for post-copulatory processes favoring monandrous sons and discusses potential explanations for the unexpected bias in paternity.

scholarly journals Male responses to sperm competition when rivals vary in number and familiarity

2019 ◽  
Vol 286 (1895) ◽  
pp. 20182589 ◽  
Author(s):  
Samuel J. Lymbery ◽  
Joseph L. Tomkins ◽  
Leigh W. Simmons
Keyword(s):  
Sperm Competition ◽  
Callosobruchus Maculatus ◽  
Kin Recognition ◽  
Reproductive Investment ◽  
Seed Beetle ◽  
Total Level ◽  
Social Familiarity

Males of many species adjust their reproductive investment to the number of rivals present simultaneously. However, few studies have investigated whether males sum previous encounters with rivals, and the total level of competition has never been explicitly separated from social familiarity. Social familiarity can be an important component of kin recognition and has been suggested as a cue that males use to avoid harming females when competing with relatives. Previous work has succeeded in independently manipulating social familiarity and relatedness among rivals, but experimental manipulations of familiarity are confounded with manipulations of the total number of rivals that males encounter. Using the seed beetle Callosobruchus maculatus , we manipulated three factors: familiarity among rival males, the maximum number of rivals encountered simultaneously and the total number of rivals encountered over a 48 h period. Males produced smaller ejaculates when exposed to more rivals in total, regardless of the maximum number of rivals they encountered simultaneously. Males did not respond to familiarity. Our results demonstrate that males of this species can sum the number of rivals encountered over separate days, and therefore the confounding of familiarity with the total level of competition in previous studies should not be ignored.

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