Ejaculate quality, testes size and sperm competition in primates

  title={Ejaculate quality, testes size and sperm competition in primates},
  author={Anders Pape M{\o}ller},
  journal={Journal of Human Evolution},
  • A. Møller
  • Published 1 August 1988
  • Environmental Science
  • Journal of Human Evolution

Sperm Competition Selects for Sperm Quantity and Quality in the Australian Maluridae

Results suggest multiple ejaculate traits, as well as aspects of testicular morphology, have evolved in response to sperm competition in the Australian Maluridae, and emphasize the importance of post-copulatory sexual selection as an evolutionary force shaping macroevolutionary differences in sperm phenotype.


  • S. Lüpold
  • Biology
    Evolution; international journal of organic evolution
  • 2013
It is indicated that body size and the energy budget may also influence the evolution of ejaculate quality, although these influences appear to vary among traits.

Sperm Competition, Sperm Numbers and Sperm Quality in Muroid Rodents

Sperm quality traits improve under sperm competition in an integrated manner suggesting that a combination of all traits is what makes ejaculates more competitive.

Intraspecific variation in sperm competition success in the bulb mite: a role for sperm size

  • J. Radwan
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1996
Only sperm size was significantly correlated with sperm competition success: males producing larger sperm were more successful and ejaculates of males producing large sperm also had significantly smaller variation in sperm size, which indicates that they were able to allocate more resources to sperm but also to maintain more stable allocation per gamete.

Associations between body size, mating pattern, testis size and sperm lengths across butterflies

  • M. Gage
  • Environmental Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1994
The results suggest that sperm competition in butterflies selects for increased investment in spermatogenesis, and specifically longer fertilizing sperm, which are not selected to be minimally sized to maximize numbers for a purely raffle-based sperm competition mode.

Concordance of mammalian ejaculate features

  • A. Møller
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1991
The different measures of ejaculate quality in mammals have been improved simultaneously, apparently by a common selective force, and positive relations between ejaculate parameters are predicted.

Sperm competition and the evolution of male reproductive anatomy in rodents

It is suggested that selection for larger plugs under sperm competition may explain variation in accessory gland size, and the need to consider both sperm and non-sperm components of the male ejaculate in the context of post-copulatory sexual selection is highlighted.

Sperm wars and the evolution of male fertility.

It is argued that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity, and that research at the genomic level will identify the genes that ultimately control male fertility.

Investment in Testes and the Cost of Making Long Sperm in Drosophila

Results are discussed in terms of the costs of producing longer sperm, the correlated evolution of sperm length and body size, the relationship between breeding system and sperm production patterns, and the nature of differences between vertebrates and invertebrates in sperm production and the size of testes.

Extra-pair paternity, sperm competition and the evolution of testis size in birds

It is demonstrated that testis mass is related positively to the level of extra-pair paternity, after controlling for body size and phylogeny, and it is argued that selection has favoured increased testismass in situations of more intense sperm competition in order to retaliate against copulations by rival males.



Testes size, ejaculate quality and sperm competition in birds

The relationship between testes size, ejaculate quality, and sperm competition in birds was analysed using data collected in artificial insemination studies to hypothesized that ejaculatequality should be superior in species with intense sperm competition compared with other species.

Testis weight, body weight and breeding system in primates

The hypothesis that selection will favour the male that can deposit the largest number of sperm means that the volume of spermatogenic tissue and hence testis size is far greater in the chimpanzee than in the gorilla or orangutan, and the results support the hypothesis.


  • M. Freund
  • Biology
    Journal of reproduction and fertility
  • 1963
Sperm output per specimen and per week did not return to the levels of the pre-depletion period during a 156-day period after the completion of dso, and changes in dso may be used to measure treatment effects on spermatogenesis.

Sperm parameters and testicular volumes in Saguinus mystax.

Semen specimens were classified as normal, relative to sperm morphology, when 95% or more of the sperm in the specimen had normal morphology; 76% of the animals evaluated had normal semen specimens using this criterion.

Daily spermatozoal production, epididymal spermatozoal reserves and transit time of spermatozoa through the epididymis of the rhesus monkey.

The results indicate that sperm matures within the epididymis of this species within 5 days, even though a 265-fold difference in epidodymal reserves was found.

Semen Parameters in Macaca mulatta: Ejaculates from Random and Selected Monkeys 1

Semen samples collected by rectal probe electroejaculation techniques from groups of adult male rhesus monkeys provided data that will aid investigators who are screening animals for studies involving reproductive potential.

Sperm transport in the human female reproductive tract in relation to semen analysis characteristics and time of ovulation.

Routine semen analyses were apparently completely normal, but the incidence of sperm recovery was still only 49% (22/45), suggesting that a failure of sperm transport may have been a significant causative factor in their infertility.

Interrelationships among the characteristics of human semen and factors affecting semen-specimen quality.

  • M. Freund
  • Biology
    Journal of reproduction and fertility
  • 1962
No effect of seminal plasma on sperm motility or forward progression was noted in a complete factorial seminal-plasma-reversal study and no significant differences were observed in mean values for semen characteristics between masturbated and condom specimens.


The possible advantages to a species of internal rather than external fertilization have frequently been stressed, though one important point appears persistently to have escaped comment. In terms of