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Sperm competition and reproductive mode influence sperm dimensions and structure among snakes
(Wiley Blackwell Publishing, Inc, 2009-10)
The role of sperm competition in increasing sperm length is a controversial issue, because findings from different taxa seem contradictory. We present a comparative study of 25 species of snakes with different levels of ...
Variability in sperm form and function in the context of sperm competition risk in two Tupinambis lizards
(Wiley, 2014-10)
In polyandrous species, sperm morphometry and sperm velocity are under strong sexual selection. Although several hypotheses have been proposed to explain the role of sperm competition in sperm trait variation, this aspect ...
Current sperm competition determines sperm allocation in a Tephritid Fruit Fly
(Wiley Blackwell Publishing, Inc, 2015-05)
Sperm competition (SC) occurs when the sperm of two or more males compete for the same set of ova. Theoretical models and experimental observations indicate that the presence of rival males causes focal males to adjust ...
Intra-male sperm variability: Is there heteromorphism in scorpions (Arachnida, Scorpiones)?
(Elsevier Gmbh, 2016-03)
There is a natural range of variation in sperm morphology inside males. This variation may be adaptive or a result of poor quality control of sperm production. Sperm aggregates can also show different morphologies inside ...
Sperm parameters associated to reproductive ecology in two snakes species
(Herpetologists League, 2011-03)
The effect of temperature on sperm dynamic parameters in ectotherms in general, and reptiles in particular, remains poorly understood due to the lack of consistent evidence. As a group, snakes show considerable variability ...
Complex interactions between sperm viability and female fertility
(Nature Publishing Group, 2019-12)
Sperm viability is a major male fitness component, with higher sperm viability associated with enhanced sperm competitiveness. While many studies have focussed on sperm viability from the male fitness standpoint, its impact ...
From storage to delivery: Sperm volume and number of spermatozoa inside storage organs and ejaculates in males of Timogenes elegans (Scorpiones: Bothriuridae)
(American Arachnological Society, 2018-08)
Sperm competition influences the evolution of many reproductive traits such as gonads, sperm or genitalia. Many sperm competition analyses concentrate in testes and ejaculates. Among arachnids, scorpions constitute an ...
Testes Mass, but Not Sperm Length, Increases with Higher Levels of Polyandry in an Ancient Sex Model
(Public Library of Science, 2014-04)
There is strong evidence that polyandrous taxa have evolved relatively larger testes than monogamous relatives. Sperm size may either increase or decrease across species with the risk or intensity of sperm competition. ...
Competitive males have higher quality sperm in a monogamous social bee
(BioMed Central, 2016)
Abstract
Background
Reproductive success is determined by the interplay between mating and fertilization success. In social insect species with male-biased sex ratios and ...
Artificial insemination unveils a first-male fertilization advantage in the guppy
(Academic Press Ltd - Elsevier Science Ltd, 2017-09)
Several factors are involved in determining the outcome of sperm competition. In addition to sperm number, sperm quality and male phenotype, insemination order is often associated with skewed paternity share. Patterns of ...