scholarly journals Developmental temperature affects the expression of ejaculatory traits and the outcome of sperm competition in Callosobruchus maculatus

2014 ◽  
Vol 27 (9) ◽  
pp. 1811-1818 ◽  
Author(s):  
R. Vasudeva ◽  
D. C. Deeming ◽  
P. E. Eady
Keyword(s):  
Sperm Competition ◽  
Callosobruchus Maculatus ◽  
Developmental Temperature

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.

scholarly journals Conspecific sperm precedence in Callosobruchus subinnotatus (Coleoptera: Bruchidae): mechanisms and consequences

2007 ◽  
Vol 274 (1612) ◽  
pp. 983-988 ◽  
Author(s):  
Paul F Rugman-Jones ◽  
Paul E Eady
Keyword(s):  
Sexual Selection ◽  
Gene Flow ◽  
Sperm Competition ◽  
Reproductive Tract ◽  
Callosobruchus Maculatus ◽  
Female Reproductive Tract ◽  
Sperm Precedence ◽  
Male And Female ◽  
Mating Order ◽  
Callosobruchus Subinnotatus

Conspecific sperm precedence (CSP) has been identified as an important post-copulatory, pre-zygotic mechanism that can act to reduce gene flow between populations. The evolution of CSP is thought to have arisen as a by-product of male and female coevolution in response to intraspecific post-copulatory sexual selection. However, little is known about the mechanisms that generate CSP. When Callosobruchus subinnotatus females copulate with both C. subinnotatus and Callosobruchus maculatus males, regardless of mating order, the majority of eggs are fertilized by conspecific sperm. The low number of heterospecific fertilizations does not result from general differences in the viability of sperm in the female reproductive tract, as heterospecific sperm fertilized equivalent numbers of eggs as conspecific sperm in the absence of sperm competition. Instead, CSP results from disadvantages to heterospecific sperm that are manifest only when in competition with conspecific sperm. CSP in C. subinnotatus appears to result from two, not mutually exclusive, mechanisms. First, conspecific sperm are better able to displace heterospecific sperm from female storage. Second, conspecific sperm achieve disproportionately higher numbers of fertilizations relative to their proportional representation in the fertilization set. Thus, we provide evidence of differential sperm use from the female spermatheca.

scholarly journals Larval developmental temperature and ambient temperature affect copulation duration in a seed beetle

Behaviour ◽  
2018 ◽  
Vol 155 (1) ◽  
pp. 69-82 ◽  
Author(s):  
R. Vasudeva ◽  
D.C. Deeming ◽  
P.E. Eady
Keyword(s):  
Ambient Temperature ◽  
Callosobruchus Maculatus ◽  
Copulation Duration ◽  
Short Term ◽  
Developmental Temperature ◽  
Effects Of Temperature ◽  
Kinetic Effects ◽  
Development Temperature ◽  
Copulatory Behaviour

Abstract The effects of temperature on cellular, systemic and whole-organism processes can be short-term, acting within seconds or minutes of a temperature change, or long-term, acting across ontogenetic stages to affect an organism’s morphology, physiology and behavioural phenotype. Here we examine the effect of larval development temperature on adult copulatory behaviour in the bruchid beetle, Callosobruchus maculatus. As predicted by temperature’s kinetic effects, copulation duration was longest at the lowest ambient temperature. However, where ambient temperature was fixed and developmental temperature experimentally varied, males reared at the highest temperature were least likely to engage in copulation, whilst those reared at the lowest temperature copulated for longer. Previous research has shown males reared at cooler temperatures inseminate fewer sperm. Thus, in this species longer copulations are associated with reduced sperm transfer. We argue that knowledge of preceding ontogenetic conditions will help to elucidate the causes of variation in copulatory behaviour.

scholarly journals High developmental temperature leads to low reproduction despite adult temperature

2021 ◽  
Vol 95 ◽  
pp. 102794
Author(s):  
Marta A. Santos ◽  
Ana Carromeu-Santos ◽  
Ana S. Quina ◽  
Mauro Santos ◽  
Margarida Matos ◽  
...  
Keyword(s):  
Developmental Temperature
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