Results 81 to 90 of about 67,350 (184)
Accessory gland size increases with sperm competition intensity in Cataglyphis desert ants
Frontiers in Ecology and EvolutionIn many species, females have multiple mates, whose sperm compete for paternity. Males may subsequently invest in the increased production of sperm and/or seminal fluid. The latter is a complex mixture of proteins, peptides, and other compounds generated
Félicien Degueldre, Serge Aron
doaj +1 more source
PLoS ONE, 2008 When females are sexually promiscuous, the intensity of sperm competition for males depends on how many partners females mate with. To maximize fitness, males should adjust their copulatory investment in relation to this intensity. However, fitness costs
Melissa L Thomas, Leigh W Simmons
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Sperm design and variation in the New World blackbirds (Icteridae) [PDF]
, 2009 Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other
AF Malo +81 more
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Sperm competition affects sex allocation but not sperm morphology in a flatworm [PDF]
, 2018 Sperm competition has been shown to be an important evolutionary agent affecting the behaviour, physiology, and morphology of both males and females. One morphological trait that is particularly likely to be affected by sperm competition is sperm size ...
Janicke, Tim, Schärer, Lukas
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A review on studies of behavioural ecology of Centrobolus (Diplopoda, Spirobolida, Pachybolidae) in southern Africa [PDF]
Arthropods, 2019 Forty-two studies on fire millipedes are reviewed in which mechanisms of selection; sperm competition and cryptic female choice were studied. Approaches to: (1) quantify size dimorphism and find the selection pressures operating on the sexes, (2 ...
Mark Cooper
doaj
Alternative reproductive tactics, sperm mobility and oxidative stress in Carollia perspicillata (Seba's short-tailed bat) [PDF]
, 2017 In social systems with alternative reproductive tactics, sneakers face a higher level of sperm competition than harem males and hence are predicted to allocate more resources to ejaculates.
Fasel, N.J. +6 more
core +1 more source
The adaptive function of masturbation in a promiscuous African ground squirrel.
PLoS ONE, 2010 Studies of animal mating systems increasingly emphasize female multiple mating and cryptic sexual selection, particularly sperm competition. Males under intense sperm competition may manipulate sperm quantity and quality through masturbation, which could
Jane M Waterman
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Sperm competition in grey whales
Nature, 1988 SIR-Your legend for the drawing of grey whales taken from Cyall Watson's book Whales of the World, perpetuates the myth that a 'helper' male is necessary for successful mating in this species. The legend states that: "Only one male is involved in the actual mating; the other takes an upright position on the far side of the female, acting as a prop or ...
Ralls, Katherine +1 more
openaire +3 more sources
Sperm phenotypic plasticity in a cichlid: a territorial male's counterstrategy to spawning takeover [PDF]
, 2017 Studies of sperm competition in species with alternative reproductive tactics (ARTs) often pay attention to the differences in investments in sperm between sneakers facing a higher sperm competition risk and bourgeois males facing a lower risk.
Heg, Dik +3 more
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