1982 ◽  
Vol 119 (2) ◽  
pp. 263-281 ◽  
Author(s):  
Robert E. Page, ◽  
Robert A. Metcalf

2004 ◽  
Vol 56 (5) ◽  
pp. 458-463 ◽  
Author(s):  
Helge Schlüns ◽  
Gudrun Koeniger ◽  
Nikolaus Koeniger ◽  
Robin F. A. Moritz

2013 ◽  
Vol 368 (1613) ◽  
pp. 20120046 ◽  
Author(s):  
Stephen M. Shuster ◽  
William R. Briggs ◽  
Patricia A. Dennis

Multiple mating by females is widely thought to encourage post-mating sexual selection and enhance female fitness. We show that whether polyandrous mating has these effects depends on two conditions. Condition 1 is the pattern of sperm utilization by females; specifically, whether, among females, male mating number, m (i.e. the number of times a male mates with one or more females) covaries with male offspring number, o . Polyandrous mating enhances sexual selection only when males who are successful at multiple mating also sire most or all of each of their mates' offspring, i.e. only when Cov ♂ ( m , o ), is positive. Condition 2 is the pattern of female reproductive life-history; specifically, whether female mating number, m , covaries with female offspring number, o . Only semelparity does not erode sexual selection, whereas iteroparity (i.e. when Cov ♀ ( m , o ), is positive) always increases the variance in offspring numbers among females, which always decreases the intensity of sexual selection on males. To document the covariance between mating number and offspring number for each sex, it is necessary to assign progeny to all parents, as well as identify mating and non-mating individuals. To document significant fitness gains by females through iteroparity, it is necessary to determine the relative magnitudes of male as well as female contributions to the total variance in relative fitness. We show how such data can be collected, how often they are collected, and we explain the circumstances in which selection favouring multiple mating by females can be strong or weak.


Nature ◽  
1986 ◽  
Vol 323 (6091) ◽  
pp. 798-800 ◽  
Author(s):  
Kenneth G. Ross

Andrology ◽  
2013 ◽  
Vol 1 (2) ◽  
pp. 251-255 ◽  
Author(s):  
A. W. Pastuszak ◽  
W. S. Lai ◽  
T.-C. Hsieh ◽  
L. I. Lipshultz

2002 ◽  
Vol 80 (2) ◽  
pp. 260-270 ◽  
Author(s):  
Anna Karlsson ◽  
Martin Haase

Hermaphroditic mating behaviour is poorly investigated and understood, especially in internally fertilized species. This study describes the mating behaviour and reproduction of the simultaneous hermaphrodite Aeolidiella glauca. Unlike other nudibranchs, A. glauca was found to transfer sperm via external spermatophores that were attached to the partner's back. Despite an elaborate courtship, the actual spermatophore transfer, which always involved two animals only, was of short duration. In most matings (88%) spermatophores were reciprocally exchanged. Shortly after transfer the ventral spermatophore cover dissolved and some sperm gathered on the epidermis. A few even penetrated epidermal cells, occasionally causing considerable damage. Most sperm, however, migrated along the body surface towards the gonopore. Migrating sperm needed 4–5 h to reach and enter the gonopore, but sperm consumption by the recipient sometimes delayed this process. Almost 30% of spermatophores fell off soon after transfer, but spermatophores from reciprocal matings and those placed in certain positions stayed on for longer. Slugs mated readily with different partners and egg production was very high. However, sperm from a single mating may not suffice to fertilize all eggs. Aeolidiella glauca's unique mating behaviour may offer ample opportunities for both sperm competition and alternative sperm utilization.


Author(s):  
J. Corley ◽  
M. Rabinovich ◽  
M. Seigelchifer ◽  
E. Corley ◽  
J. ZorzÓpulos

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