Peculiarities of sperm production by anadromous and parr Atlantic salmon (<i>Salmo salar</i> L.) and fish cultural characteristics of such sperm

Казаков, Р. В.

doi:10.1111/j.1095-8649.1981.tb03753.x

Cited by 54 publications

(29 citation statements)

References 3 publications

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“…Mechanisms for competition range from multiple copulation to larger ejaculates, depending on the capacity to store sperm, but in species with external fertilization sperm placement can also be optimized, and this is probably the main challenge to mature parr. Studies on the characteristics of ejaculates from parr and migrant males (Kazacov 1981) found that sperm concentration and activity did not differ between these male types and that the average ejaculate size of migrant males is 20-30 times as large as the ejaculate volume of parr, larger than the parr's total gonad weight. Furthermore, parr allocate a larger fraction of their energies to reproduction (Gage et al 1995), having gonadosomatic indexes (gonad weight\total body weight) of around 4.65 % compared with only 2.33 % in migrant males.…”

Section: Discussion and Conclusion (A) Parr Body Size And Reproductimentioning

confidence: 99%

“…The fact that, in section 8, where two sets of six parr were allowed to spawn consecutively with the anadromous pair, parr success increased when new parr were added, can be taken as evidence that the decrease in success in the second egg pocket was not due to an increase in the aggressiveness of the anadromous male or female, as the same migrant pair experienced an increase in parr success when new parr replaced the old. Unfortunately, there is a scarcity of data on spermatogenesis in mature male parr, although there is some evidence that sperm production is enhanced during the spawning period (Kazacov 1981).…”

Section: Discussion and Conclusion (A) Parr Body Size And Reproductimentioning

confidence: 99%

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Alternative reproductive tactics in atlantic salmon: factors affecting mature parr success

Thomaz

Beall

Burke

1997

Proc. R. Soc. Lond. B

132

134

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SUMMARYIn Atlantic salmon, as in most salmonids, males can mature early in the life cycle, as small freshwater fish, termed parr, and\or undergo a sea migration before maturing as full-size adults. The alternative life histories are contingent on environmental and social circumstances, such as growth rate, territory quality or any other factor that affects the individual's state. In order to model the choice of life history in this group of commercially valuable species, it is necessary to understand not only the relative contribution of the different male types to subsequent generations, but also to know the factors that affect reproductive success in each type.In this paper we present the results of a study designed to investigate the factors that affect the reproductive success of mature parr. We used highly polymorphic minisatellite DNA markers to analyse paternity in a series of mating experiments where the number and body size of parr were manipulated. The fraction of eggs fertilized by mature parr ranged from 26 to 40 %, with individual parr fertilizing up to 26 % of the eggs. A strong positive correlation was found between parr size and reproductive success. The relative success of parr decreased with increasing parr number. Data from this and other studies on variation in the timing and degree of parr reproductive success are discussed in relation to the evolution of male mating strategies and life history in salmonids.

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Section: Discussion and Conclusion (A) Parr Body Size And Reproductimentioning

confidence: 99%

Section: Discussion and Conclusion (A) Parr Body Size And Reproductimentioning

confidence: 99%

Alternative reproductive tactics in atlantic salmon: factors affecting mature parr success

Thomaz

Beall

Burke

1997

Proc. R. Soc. Lond. B

132

134

View full text Add to dashboard Cite

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“…We found no effect of male size on fertilization success where behavioral competition, sperm competition and spawning history were eliminated as contributing factors. Larger males may have had greater ejaculate volumes (Kazakov 1981, Gjerde 1984; however, this apparently did not benefit larger males in our study, probably because ejaculate volumes of small males were more than adequate for maximum fertilization (Hoysak & Liley 2001).…”

Section: Discussionmentioning

confidence: 51%

Male size effects on fertilization success: lack of evidence in chinook salmon spawning under experimental conditions

Berejikian

Tezak

2005

Environ Biol Fish

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“…In nematodes and teleosts, males therefore appear to be penalized less by small size (Charnov & Bull 1977, Conover 1984. For example, whereas gamete production in teleosts may be relatively unconstrained by male body size (Kazamov 1981), fecundity is known to increase with maternal size (e.g., Bagenal1966, Docker et al 1986, Hay & Brett 1988. Egg number and female length are likewise correlated in lampreys (Hardisty 1964, Kott 1971, Beamish & Thomas 1983, Docker & Beamish 1991).…”

Section: Streammentioning

confidence: 99%

Age, growth, and sex ratio among populations of least brook lamprey,Lampetra aepyptera, larvae: an argument for environmental sex determination

1994

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SynopsisSex ratios of least brook lamprey, Lampetra aepyptera, larvae varied widely among 12 geographically-diverse streams of the eastern United States. The extremes were 29 and 71% male, and the proportion of males increased significantly with relative population density, which was estimated among the streams from the number of larvae collected per m2 of substrate. The skewed sex ratios were not likely due to differential mortality between the sexes or differential recruitment to the adult stock, since they were established at the time of gonadal differentiation (at ca. 2 years of age) and remained relatively constant over the subsequent 2-3 years of larval life. Furthermore, although females seemed to predominate in the oldest larval age class, thus appearing to metamorphose later than males, their numbers were small and were omitted from the overall sex ratio. Sex ratio did not vary significantly with water hardness, pH, annual thermal units, or latitude. The possible adaptive significance of density-dependent sex determination in lampreys, however, remains elusive. It has been proposed that growth-promoting conditions might yield female-biased sex ratios as a tactic for ensuring that relatively large individuals become females, thereby increasing their fecundity. As predicted, larval size at a given age was generally greater in low-density populations, but there was no relationship between sex ratio and larval size, and female larvae were not consistently larger than the males.

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Peculiarities of sperm production by anadromous and parr Atlantic salmon (Salmo salar L.) and fish cultural characteristics of such sperm

Cited by 54 publications

References 3 publications

Alternative reproductive tactics in atlantic salmon: factors affecting mature parr success

Alternative reproductive tactics in atlantic salmon: factors affecting mature parr success

Male size effects on fertilization success: lack of evidence in chinook salmon spawning under experimental conditions

Age, growth, and sex ratio among populations of least brook lamprey,Lampetra aepyptera, larvae: an argument for environmental sex determination

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