• Publications
  • Influence
Sperm competition, male prudence and sperm-limited females
TLDR
This work focuses on studies showing that males assess mating status and relative fecundity of females, and reveals that modulation of ejaculate investment by males can sometimes result in sperm limitation for females.
Sperm Competition in Fishes: The Evolution of Testis Size and Ejaculate Characteristics
TLDR
It is found that both the gonadosomatic index and sperm numbers increase with intensity of sperm competition across species but that sperm length decreases, which does not fit predictions of current sperm competition theory.
Effects of alternative male mating strategies on characteristics of sperm production in the Atlantic salmon (Salmo salar): theoretical and empirical investigations
TLDR
Results show that parr invest relatively more heavily into total spermatogenesis, and have a larger gonosomatic index than anadromous males, which may explain how male parr, under elevated risks of sperm competition and occupying a disfavoured mating role, achieve disproportionately high fertilization success.
Sperm competition games: individual assessment of sperm competition intensity by group spawners
TLDR
Three sperm competition game models devised mainly for externally fertilizing group-spawning species such as many fish predict that males should decrease their sperm expenditure as the estimated number of competitors present at a given spawning increases above two.
Sperm competition games: a prospective analysis of risk assessment
TLDR
The logic of assessment of sperm Competition risk by individual males where the mechanism of sperm competition follows a ‘loaded raffle’ is developed and biological evidence for the predictions is summarized and discussed.
Spermatozoal Traits and Sperm Competition in Atlantic Salmon Relative Sperm Velocity Is the Primary Determinant of Fertilization Success
TLDR
Natural variation in spermatozoal traits among wild Atlantic salmon, a species naturally adapted to sperm competition, is used to examine how the relative influences of sperm number, velocity, longevity, and total length determine sperm competition success.
Associations between body size, mating pattern, testis size and sperm lengths across butterflies
  • M. Gage
  • Biology
    Proceedings of the Royal Society of London…
  • 22 December 1994
TLDR
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.
Continuous variation in reproductive strategy as an adaptive response to population density in the moth Plodia interpunctella
  • M. Gage
  • Biology
    Proceedings of the Royal Society of London…
  • 22 July 1995
TLDR
These results suggest that developing male P. interpunctella detect signals which reflect larval population structure, and hence eventual mating pattern, and therefore appear to invest in competence for mating and sperm competition.
Quick-change artists: male plastic behavioural responses to rivals.
TLDR
It is found that plasticity in males is widespread and not dominated by responses that occur pre- or post-copulation, as well as the limited data on the ultimate fitness consequences of such plastic behaviour.
Reduced Heterozygosity Depresses Sperm Quality in Wild Rabbits, Oryctolagus cuniculus
TLDR
It is shown, for a wild mammal, that inbreeding is associated with decreased sperm quality, confirming suggestions of links between inbreeding and elevated sperm abnormalities in rare felids.
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