Smolt development and subsequent sexual maturity in previously mature male Atlantic salmon (Salmo salar)

The genetic influence of stocking on the Atlantic salmon (Salmo salar) population from the Spanish Esva River was analysed by electrophoresis of protein loci. Genetic variation within parr and mature male parr samples demonstrated that Scottish-origin parr stocked in 1990 survived the first summer. However, samples collected from returning adults in 1990 and 1991 did not indicate any contribution from previous stocking programs. Altered MEP-2* frequencies indicate that the native gene pool may have been disrupted by foreign genomes from precocious males or grilse.

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The impact of two pesticides on olfactory-mediated endocrine function in mature male Atlantic salmon (Salmo salar L.) parr

Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology ◽

10.1016/s1096-4959(01)00321-9 ◽

2001 ◽

Vol 129 (2-3) ◽

pp. 269-276 ◽

Cited By ~ 72

Author(s):

Andrew Moore ◽

Nicola Lower

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Mature Male ◽

Endocrine Function ◽

Atlantic Salmon Salmo Salar ◽

The Impact

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Age at Sexual Maturity in Icelandic Stocks of Atlantic Salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f83-168 ◽

1983 ◽

Vol 40 (9) ◽

pp. 1456-1468 ◽

Cited By ~ 47

Author(s):

Dennis L. Scarnecchia

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Sexual Maturity ◽

Physical Factors ◽

Thermal Gradients ◽

Ocean Temperature ◽

Growth And Survival ◽

Atlantic Salmon Salmo Salar ◽

Life History Pattern ◽

Second Year

For Icelandic stocks of Atlantic salmon (Salmo salar) in 77 rivers, the combination of June ocean temperature, length of river ascended by the salmon, discharge of the river in July–September, and latitude explained much of the variation in percentages of grilse — 72% for females and 62% for males. For both sexes, percentage of grilse was directly related to ocean temperature but inversely related to length of river, discharge of river, and latitude. For stocks in 23 Southwest Coast rivers, length of river explained 72% of the variation in percentage of females that were grilse. Females in stocks south of the thermal gradients separating Atlantic from Arctic or Polar water tended to return as grilse; females north of the gradients tended to return after more than one winter at sea. The decline in percentages of grilse clockwise from southwestern to northeastern rivers corresponded closely with the decline in June ocean temperatures between these areas. I hypothesize that the salmon stocks have adapted their age at sexual maturity to the length and discharge of the rivers, natural mortality rates during their second year at sea, and average expected ocean temperatures, reflecting conditions for growth and survival, that the smolts encounter. Age at maturity appears not to be a direct causal response to any of these physical factors, and appears best understood only with reference to the entire life history pattern of each stock.

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Importance of the Variation in Life History Parameters of Atlantic Salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f85-080 ◽

1985 ◽

Vol 42 (3) ◽

pp. 615-618 ◽

Cited By ~ 56

Author(s):

Richard L. Saunders ◽

Charles B. Schom

Keyword(s):

Life History ◽

Atlantic Salmon ◽

Population Size ◽

Salmo Salar ◽

Great Variability ◽

Mature Male ◽

Life History Parameters ◽

Atlantic Salmon Salmo Salar ◽

Sexually Mature ◽

Mature Male Parr

Atlantic salmon (Salmo salar) demonstrate great variability in their life history; individuals from a given year-class can spawn during several years and can, therefore, breed with salmon from other year-classes. Atlantic salmon can mature after 1–4 sea-winters and some males mature as parr, during the second through fifth years, before going to sea. Salmon may survive to spawn more than once; some spawn several times. This variability in life history may be a safeguard against loss of small stocks through several successive years of reproductive failure, since nonspawning individuals in the river or at sea could spawn in subsequent years. Spawning populations are frequently quite small. The effective spawning population size may be potentially much larger, however, since members of several year-classes, including sexually mature male parr and anadromous adults of various ages, contribute to spawning. The level of inbreeding may be relatively low, since a number of year-classes, each with different sets of parents, are represented during spawning.

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Significance of Mature Male Parr in a Small Population of Atlantic Salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-119 ◽

1989 ◽

Vol 46 (6) ◽

pp. 928-931 ◽

Cited By ~ 32

Author(s):

Jan Hennsng L'abée-Lund

Keyword(s):

Atlantic Salmon ◽

Population Size ◽

Effective Population Size ◽

Salmo Salar ◽

Small Population ◽

Mature Male ◽

Effective Population ◽

Atlantic Salmon Salmo Salar ◽

Mature Male Parr

The spawning population of Atlantic salmon, Salmo salar, (mature male parr and adults (anadromous salmon)) were assessed in the River Baevra, central Norway, when the river was treated with rotenone in November 1986. The spawning population of adults consisted of 15 males and 19 females. The spawning population of males consisted of 167 mature male parr per adult male. The effective population size of adults was small; Na = 33.5 individuals. The presence of mature male parr theoretically increased the effective population size to Na = 71.7 individuals. This increase indicated that mature male parr brought the effective population size above a recommended minimum (Na = 50) to ensure long term viability.

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Spawning behaviour and success of mature male Atlantic salmon (Salmo salar) parr of farmed and wild origin

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f05-032 ◽

2005 ◽

Vol 62 (5) ◽

pp. 1153-1160 ◽

Cited By ~ 33

Author(s):

Laura K Weir ◽

Jeffrey A Hutchings ◽

Ian A Fleming ◽

Sigurd Einum

Keyword(s):

Reproductive Success ◽

Atlantic Salmon ◽

Salmo Salar ◽

First Generation ◽

Large Male ◽

Mature Male ◽

Atlantic Salmon Salmo Salar ◽

Spawning Behaviour ◽

Mature Male Parr ◽

Variance In Reproductive Success

We examined genetic differences in the reproduction of an alternative maturation phenotype in Atlantic salmon (Salmo salar) by comparing the spawning behaviour and success among farmed, first-generation hybrid, and wild mature male parr raised in similar environments. Parr competed for spawning opportunities in the presence of either wild or farmed large males. There were no consistent differences among groups in aggression; however, there were differences in spawning participation with respect to large male origin and among parr types. There was a strong negative temporal effect on mature male parr spawning participation that differed by parr type; wild and farmed parr were most likely to participate in early spawnings, with hybrids being the most likely to participate in late spawnings. Overall, parr were also less likely to participate in spawnings involving large farmed males. Variance in reproductive success was higher among parr than among large males. Our results are consistent with the hypothesis that there are genetically based behavioural differences among mature male parr of farmed and wild origin that may potentially lead to differences in reproductive success.

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