scholarly journals Sperm competition, alternative mating tactics and context-dependent fertilization success in the burying beetle, Nicrophorus vespilloides

2007 ◽  
Vol 274 (1615) ◽  
pp. 1309-1315 ◽  
Author(s):  
Clarissa M House ◽  
John Hunt ◽  
Allen J Moore
Keyword(s):  
Sperm Competition ◽  
Fertilization Success ◽  
Mating Strategies ◽  
Alternative Mating Tactics ◽  
Sterile Male ◽  
Burying Beetle ◽  
Mating Tactics ◽  
Competition Theory ◽  
Nicrophorus Vespilloides ◽  
Biological Context

Fertilization success in sperm competition is often determined by laboratory estimates of the proportion of offspring sired by the first ( P 1 ) or second ( P 2 ) male that mates. However, inferences from such data about how sexual selection acts on male traits in nature may be misleading if fertilization success depends on the biological context in which it is measured. We used the sterile male technique to examine the paternity of the same male in two mating contexts in the burying beetle, Nicrophorus vespilloides , a species where males have alternative mating strategies based on the presence or absence of resources. We found no congruence in the paternity achieved by a given male when mating under different social conditions. P 2 estimates were extremely variable under both conditions. Body size was unrelated to success in sperm competition away from a carcass but, most probably through pre-copulatory male–male competition, influenced fertilization success on a carcass. The contribution of sperm competition is therefore dependent on the conditions under which it is measured. We discuss our findings in relation to sperm competition theory and highlight the need to consider biological context in order to link copulation and fertilization success for competing males.

Fertilization dynamics of sperm from different male mating tactics in bluegill (Lepomis macrochirus)

2005 ◽  
Vol 83 (12) ◽  
pp. 1638-1642 ◽  
Author(s):  
Albrecht I Schulte-Hostedde ◽  
Gary Burness
Keyword(s):  
Sperm Competition ◽  
Lepomis Macrochirus ◽  
Fertilization Success ◽  
Male Mating ◽  
Motile Sperm ◽  
Mating Tactics ◽  
Sperm Activation ◽  
Competition Theory ◽  
Sperm Density ◽  
Over Time

Sperm competition results in the evolution of ejaculate characteristics such as high sperm density, high motility, and fast sperm swimming speed. A fundamental assumption of sperm competition theory is that ejaculates with high motility and fast-swimming sperm have an advantage with respect to fertilization success. We tested this assumption by studying the fertilization dynamics of alternative mating tactics (cuckolders and parentals) of male bluegill (Lepomis macrochirus Rafinesque, 1819). Sneakers (cuckolders) have faster swimming sperm and a higher proportion of motile sperm immediately following sperm activation than do parentals; however, these variables decline more quickly over time in sneaker sperm than in the sperm of parental males. We used a controlled fertilization experiment to test the prediction that parental males will have higher fertilization success than sneakers late in the sperm activation cycle because of the reduced rate of decline in ejaculate quality over time. We found that as the time from sperm activation increases parental sperm fertilizes more eggs than the sperm of sneakers. Our results support the idea that fertilization success is higher when ejaculates contain a higher proportion of either motile sperm or faster swimming sperm, all else being equal. In addition, after controlling for time from sperm activation, we found a significant bias in fertilization success toward parental males, suggesting that cryptic female choice might play a role in fertilization dynamics.

scholarly journals Experience does not alter alternative mating tactics in the burying beetle Nicrophorus vespilloides

2008 ◽  
Vol 20 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Craig A. Walling ◽  
Clare E. Stamper ◽  
Claire L. Salisbury ◽  
Allen J. Moore
Keyword(s):  
Alternative Mating Tactics ◽  
Burying Beetle ◽  
Mating Tactics ◽  
Nicrophorus Vespilloides

scholarly journals Alternative mating tactics and tactical deception: Is the common cuttlefish (Sepia officinalis) nothing but a common cheat?

2017 ◽  
Author(s):  
Gavan M Cooke ◽  
Claire Johnson ◽  
Tony Reed ◽  
Andrew C Jackson
Keyword(s):  
Reproductive Strategies ◽  
Mating Strategies ◽  
Alternative Mating Tactics ◽  
Mating Tactics ◽  
Female Mimicry ◽  
Tactical Deception ◽  
Ideal System ◽  
The Common ◽  
Behavioural Factors ◽  
New Evidence

AbstractAlternative mating tactics (AMTs) are common in the animal kingdom, yet much work remains before their evolution and role in driving sexual selection is fully understood. Utilizing features of citizen science, we present compelling evidence that a third species in the cuttlefish genusSepia(Cephalopoda) possess males who use sneaky mating and female mimicry as alternative strategies to conspicuous signalling and fighting. We also present new evidence of large aggregations (n~30) in this species that possibly drive alternative mating strategies. Lastly, we provide footage of an opportunistic sneaky copulation in this species. We believe that alternative mating tactics may be more common in this genus than previously recorded (based on observations presented here and a search of the literature for similar life history, environmental and behavioural factors found in other species within theSepiagenus), and as much of their captive husbandry is well known, they could an ideal system for studying the evolution of alternative reproductive strategies.

Effects of alternative male mating strategies on characteristics of sperm production in the Atlantic salmon ( Salmo salar ): theoretical and empirical investigations

1995 ◽  
Vol 350 (1334) ◽  
pp. 391-399 ◽  
Keyword(s):  
Atlantic Salmon ◽  
Sperm Competition ◽  
Salmo Salar ◽  
Reproductive Traits ◽  
Fertilization Success ◽  
Mating Strategies ◽  
Male Mating ◽  
Sperm Length ◽  
Male Mating Strategies ◽  
Natural Variance

Atlantic salmon ( Salmo salar ) males mature as either tiny precocious parr before seaward migration, or as older and larger anadromous males. Anadromous males dominate the spawning redds and aggressively defend females against parr intrusions. Parr gain fertilizations by sneaking in to ejaculate while anadromous males and females spawn. Such differences in mating advantage generate asymmetries in risk of sperm competition between the male strategies. Theoretical sperm competition models predict that males typically mating in disfavoured roles (here, the parr strategy) should be selected to offset this disadvantage by investing more into spermatogenesis to achieve fertilization success. First, we present a theoretical model which analyses gametic expenditure for salmon parr and anadromous male reproductive strategies. We then use the natural variance in mating pattern within this species to compare empirically how males invest in spermatogenesis. A range of reproductive traits were measured for both male strategies. Absolutely, anadromous males have larger testes and produce greater numbers of sperm than parr males. However, results show that parr invest relatively more heavily into total spermatogenesis, and have a larger gonosomatic index than anadromous males. Relative to body size, parr produced greater numbers of sperm and volumes of stripped ejaculate. There was no difference in sperm length between the two male strategies. However, more sperm were motile in parr ejaculates, and these sperm lived longer than anadromous male sperm. Our findings may explain how male parr, under elevated risks of sperm competition and occupying a disfavoured mating role (parr weigh only 0.15% of the average body mass of anadromous males) achieve disproportionately high fertilization success.

Effects of timing of nest entry and body size on the fertilization success of alternative male reproductive phenotypes of masu salmon (Oncorhynchus masou)

2008 ◽  
Vol 86 (10) ◽  
pp. 1121-1130 ◽  
Author(s):  
M. Watanabe ◽  
S. Takamura ◽  
K. Maekawa
Keyword(s):  
Body Size ◽  
Parentage Analysis ◽  
Fertilization Success ◽  
Masu Salmon ◽  
Mature Male ◽  
Alternative Mating Tactics ◽  
Oncorhynchus Masou ◽  
Mating Tactics ◽  
Mature Male Parr ◽  
Masu Salmon Oncorhynchus Masou

Using a natural population of masu salmon ( Oncorhynchus masou (Brevoort, 1856)) in a stream of Shikaribetsu Lake, Hokkaido, Japan, we combined behavioural observations with genetic parentage analysis to explore the factors affecting fertilization success achieved by alternative mating tactics (fighting by large migratory males and sneaking by small mature male parr). Larger males gained priority access to females; migrant males do this by holding a guarding position near the nesting female and mature male parr do this by adopting sneaker behaviour and attending spawning groups. Status of mature male parr was related to success of nest entry but not to timing of nest entry, although the timing of nest entry influenced fertilization success of sneakers and ejaculation simultaneous with pair spawning was needed for fertilization by sneakers. The relative body size of each male who successfully spawned with a female is also likely to determine the proportion of eggs he fertilized because larger males have larger ejaculate. These results provide insight into factors relating to variation in fertilization success, how body size dimorphisms may be related to fitness, and evolution of alternative mating tactics.

scholarly journals A sexual network approach to sperm competition in a species with alternative mating tactics

2014 ◽  
Vol 26 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Danilo G. Muniz ◽  
Paulo R. Guimarães ◽  
Bruno A. Buzatto ◽  
Glauco Machado
Keyword(s):  
Sperm Competition ◽  
Alternative Mating Tactics ◽  
Network Approach ◽  
Mating Tactics ◽  
Sexual Network

scholarly journals Tactic-specific differences in seminal fluid influence sperm performance

2013 ◽  
Vol 280 (1755) ◽  
pp. 20122891 ◽  
Author(s):  
Lisa Locatello ◽  
Federica Poli ◽  
Maria B. Rasotto
Keyword(s):  
Sperm Competition ◽  
Seminal Fluid ◽  
Fertilization Rate ◽  
Fertilization Success ◽  
Mating Tactics ◽  
Recognition Mechanism ◽  
Self Recognition ◽  
Sperm Competition Risk ◽  
Grass Goby ◽  
Zosterisessor Ophiocephalus

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby ( Zosterisessor ophiocephalus ) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

scholarly journals Correlates of reproductive success within alternative mating tactics of the common shrew

1996 ◽  
Vol 7 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Paula Stockley ◽  
Jeremy B. Searle ◽  
David W. Macdonald ◽  
Catherine S. Jones
Keyword(s):  
Reproductive Success ◽  
Common Shrew ◽  
Alternative Mating Tactics ◽  
Mating Tactics ◽  
The Common
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