Mate and sperm competition during multiple-male spawnings of Atlantic salmon

Mjølnerød, I. B.; Fleming, Ian A.; Refseth, Unn Hilde; Hindar, Kjetil

doi:10.1139/z97-173

Cited by 71 publications

(33 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, individual parr often obtain very little reproductive success in (experimental) spawning events (e.g., Thomaz et al 1997;Hutchings 2001, 2002;Weir et al 2005) as mature parr also establish dominance hierarchies during spawning (Hutchings and Myers 1988;Fleming 1996). Instead, N e may be mainly affected by the reproductive variance of anadromous males (Mjølnerod et al 1998;Jones and Hutchings 2002). We find some support for this assertion through a positive relation between annual N b estimates and the number of anadromous males in Middle Brook.…”

Section: Discussionmentioning

confidence: 72%

“…In Newfoundland, male parr typically mature at ages 11 and 21 (Dalley et al 1983;Myers et al 1986;Hutchings 2002 Age-specific survivorship values (l x ) were then calculated as l x ¼ Q x i¼1 s i , for each sex and age class x in a population. For anadromous fish, age-and sex-specific birth rates (b x ) were estimated, using proportions of adults in the various age classes, weighted by body size (wet weight), as a proxy for relative fecundity (Fleming et al 1997;Mjølnerod et al 1998;Garant et al 2001;but see O'Connell et al 2008). We attempted to account for the influence of male parr maturation on age-specific reproductive contribution of males as follows.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Age Structure, Changing Demography and Effective Population Size in Atlantic Salmon (Salmo salar)

2009

View full text Add to dashboard Cite

Effective population size (N e ) is a central evolutionary concept, but its genetic estimation can be significantly complicated by age structure. Here we investigate N e in Atlantic salmon (Salmo salar) populations that have undergone changes in demography and population dynamics, applying four different genetic estimators. For this purpose we use genetic data (14 microsatellite markers) from archived scale samples collected between 1951 and 2004. Through life table simulations we assess the genetic consequences of life history variation on N e . Although variation in reproductive contribution by mature parr affects age structure, we find that its effect on N e estimation may be relatively minor. A comparison of estimator models suggests that even low iteroparity may upwardly bias N e estimates when ignored (semelparity assumed) and should thus empirically be accounted for. Our results indicate that N e may have changed over time in relatively small populations, but otherwise remained stable. Our ability to detect changes in N e in larger populations was, however, likely hindered by sampling limitations. An evaluation of N e estimates in a demographic context suggests that life history diversity, density-dependent factors, and metapopulation dynamics may all affect the genetic stability of these populations.

show abstract

Section: Discussionmentioning

confidence: 72%

mentioning

confidence: 99%

Age Structure, Changing Demography and Effective Population Size in Atlantic Salmon (Salmo salar)

2009

View full text Add to dashboard Cite

show abstract

“…Male breeding success was calculated as the number of live embryos recovered from nests that they fertilized and, in cases of multiple-male paternity (9% of spawnings involved both farm and native males), it was calculated following the method of Fleming et al (1996). This method incorporates the order of male precedence at spawning, which is an important determinant of fertilization success in Atlantic salmon (MjÖlnerÖd et al 1998).…”

Section: (A) Anadromous Adults and Breeding Successmentioning

confidence: 99%

Lifetime success and interactions of farm salmon invading a native population

Fleming

Hindar

Mjølnerød

et al. 2000

Proc. R. Soc. Lond. B

476

566

View full text Add to dashboard Cite

Farm Atlantic salmon escape and invade rivers throughout the North Atlantic annually, which has generated growing concern about their impacts on native salmon populations. A large-scale experiment was therefore undertaken in order to quantify the lifetime success and interactions of farm salmon invading a Norwegian river. Sexually mature farm and native salmon were genetically screened, radio tagged and released into the River Imsa where no other salmon had been allowed to ascend. The farm ¢shes were competitively and reproductively inferior, achieving less than one-third the breeding success of the native ¢shes. Moreover, this inferiority was sex biased, being more pronounced in farm males than females, resulting in the principal route of gene £ow involving native males mating with farm females. There were also indications of selection against farm genotypes during early survival but not thereafter. However, evidence of resource competition and competitive displacement existed as the productivity of the native population was depressed by more than 30%. Ultimately, the lifetime reproductive success (adult to adult) of the farm ¢shes was 16% that of the native salmon. Our results indicate that such annual invasions have the potential for impacting on population productivity, disrupting local adaptations and reducing the genetic diversity of wild salmon populations.

show abstract

“…Behavioural observations and associated male sound production of haddock has also been studied in communal spawning tanks (Hawkins and Amorim, 2000). In Atlantic salmon (Salmo salar), male fertilization success was influenced by a variety of factors, including sperm precedence, male size, and spawning history with sperm limitation likely influencing individual success (Mjolnerod et al, 1998). Group spawns resulted in higher egg fertilization rates compared to mono-male spawns in bluehead wrasse (Thalassoma bifasciatum; Robertson, 1996), though no difference was noted for cod when one compared to two males were mated with a female (Rakitin et al, 2001).…”

Section: Male Fertilization Success Sperm Competitionmentioning

confidence: 99%

Estimation of Male Reproductive Success of Marine Fisheries

Trippel¹

2003

J. Northw. Atl. Fish. Sci.

View full text Add to dashboard Cite

The subject of reproductive potential of fish populations is dominated by studies on the female gender. Studies on male reproduction are relatively few, but have increased in number during the previous decade. The objectives of this contribution were to describe and quantify the reproductive traits that make up the viable sperm production of a population. Some of these reproductive traits were easily measured from wild fish (e.g., mature testes weight), and others were more easily measured on captive fish (e.g., fertilization potential and sperm motility). Results of laboratory and field studies were then integrated to generate estimates of viable sperm production of a fish stock. A number of experimental protocols have been employed over the years to assess male fertility. The strengths and weaknesses of the different experimental approaches were reviewed and appropriate recommendations given towards establishing standardized protocols. Although the review is broad in nature, and includes references to a number of marine fishes, it concentrated on exploited species that occur in the North Atlantic and Baltic Sea within the taxonomic groups gadoidae, pleuronectoidae and clupeidae (Clupeiformes). In addition, published data on male reproductive traits of species in these taxa were tabulated and summarized. The terms of interest included sex ratio, maturity state, testes weight, sperm fertilization potential (artificial fertilization and paired mating), sperm density, sperm motility and paternal effects on early life history traits.An equation for determinate spawners was described that quantifies a population's viable sperm production using data on adult body characteristics and associated quantity and quality of sperm. The equation was used to establish time series of viable sperm production for Atlantic cod (Gadus morhua) of Newfoundland and Labrador. Results indicated on average 1 600 billion viable sperm were released to produce one recruit at age 3 years but with substantial variation among years in relation to changes in stock composition and growth as well as stock size. Distinct peaks in the number of viable sperm in 1981 and 1986 corresponded to distinct peaks in the number of age 3 recruits in those same years.

show abstract

Mate and sperm competition during multiple-male spawnings of Atlantic salmon

Cited by 71 publications

References 21 publications

Age Structure, Changing Demography and Effective Population Size in Atlantic Salmon (Salmo salar)

Age Structure, Changing Demography and Effective Population Size in Atlantic Salmon (Salmo salar)

Lifetime success and interactions of farm salmon invading a native population

Estimation of Male Reproductive Success of Marine Fisheries

Contact Info

Product

Resources

About