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

1985 ◽  
Vol 42 (3) ◽  
pp. 615-618 ◽  
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.

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

1989 ◽  
Vol 46 (6) ◽  
pp. 928-931 ◽  
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.

Parr–Smolt Transformation in Female and Sexually Mature Male Anadromous and Nonanadromous Atlantic Salmon, Salmo salar

1986 ◽  
Vol 43 (3) ◽  
pp. 680-686 ◽  
Author(s):  
Tim P. Birt ◽  
John M. Green
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Condition Factor ◽  
Total Lipid Content ◽  
Chloride Cell ◽  
Mature Male ◽  
Seasonal Patterns ◽  
Atlantic Salmon Salmo Salar ◽  
Sexually Mature ◽  
Mature Male Parr

The parr–smolt transformation was compared in cultured Newfoundland male and female anadromous and nonanadromous Atlantic salmon, Salmo salar. Seasonal patterns of decreasing total lipid content and condition factor accompanied by increasing moisture content, silvering, and branchial Na+-K+ ATPase activity indicate that smoltification occurred only in immature anadromous females. Previously mature anadromous males did not smoitify. In general, smoltification did not occur in nonanadromous salmon. Chloride cell length did not increase in any group with smoltification. The lack of smoltification in previously mature male parr of anadromous stock is consistent with reports of small numbers of male salmon in smolt runs in many Newfoundland rivers.

Electrophoretic Assessment of the Contribution of Transplanted Scottish Atlantic Salmon (Salmo salar) to the Esva River (Northern Spain)

1994 ◽  
Vol 51 (2) ◽  
pp. 248-252 ◽  
Author(s):  
Paloma Morán ◽  
Alberto M. Pendás ◽  
Eva Garcia-Vázquez ◽  
Jorge T. Izquierdo ◽  
Dennis T. Rutherford
Keyword(s):  
Genetic Variation ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gene Pool ◽  
Mature Male ◽  
Genetic Influence ◽  
Northern Spain ◽  
Atlantic Salmon Salmo Salar ◽  
Precocious Males ◽  
Mature Male Parr

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.

The Effect of Impoundment on the Population and Movement of Atlantic Salmon in Ellerslie Brook, Prince Edward Island

1960 ◽  
Vol 17 (4) ◽  
pp. 453-473 ◽  
Author(s):  
J. W. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Prince Edward Island ◽  
Salt Water ◽  
Mature Male ◽  
Freshwater Discharge ◽  
Age Group ◽  
Annual Variations ◽  
Sexually Mature ◽  
Mature Male Parr

During autumn spates Atlantic salmon (Salmo salar) commonly enter the small spring-fed streams of Prince Edward Island and spawn. Annual variations in freshwater discharge from Ellerslie Brook were found to determine the number of salmon and time of ascent. A pond formed on the brook created a habitat that exercised a strong retaining influence on the movements of spawners, kelts, parr, and migrating smolts. Smolts which stayed in the pond suffered heavy mortalities.Movements by sexually mature male parr, within and between fresh and salt water, occurred in the fall. Some parr remained in the estuary (0–27‰ salinity) throughout the year. The pond provided a habitat for parr.Smolt transformation at ages II and III occurred in the stream, pond, and estuary in the spring. Pond and stream smolts of the same age group were similar in size when they migrated.

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

2005 ◽  
Vol 62 (5) ◽  
pp. 1153-1160 ◽  
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.

Effect of 6-, 12-, and 18-month Photoperiod Cycles on Smolting and Sexual Maturation in Juvenile Atlantic Salmon (Salmo salar)

1992 ◽  
Vol 49 (11) ◽  
pp. 2273-2280 ◽  
Author(s):  
J. Duston ◽  
R. L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturation ◽  
Condition Factor ◽  
Temperature Cycle ◽  
Frequency Distributions ◽  
Atlantic Salmon Salmo Salar ◽  
Sexually Mature ◽  
Mature Male Parr ◽  
Modal Group

The results support the hypothesis that the commencement of smolting can occur during the decreasing phase of the annual photoperiod cycle, and sexual maturation during the increasing phase of the cycle, provided individuals have attained certain (unknown) growth thresholds. Thereafter the completion of smolting is entrained by the increasing phase of the photoperiod cycle, and sexual maturation by the decreasing phase. Three groups of Atlantic salmon (Salmo salar) were raised in freshwater for over 2 yr from the eyed egg stage under photoperiod cycles of either 6-, 12- (control), or 18-mo periodicity and an ambient 12-mo temperature cycle. Smolting was judged by changes in salinity tolerance and condition factor. All groups developed bimodal length–frequency distributions by December following hatch. Fish continued to be recruited into the upper modal group (UMG) beyond the shortest day of the photoperiod cycle, providing temperature was not limiting growth. The 6-, 12-, and 18-mo photoperiod cycles resulted in approximately 50, 60, and 100% of the populations being recruited into the UMG. Sexually mature male parr (1 + yr old) occurred only in the lower modal group of the 6- and 12-mo groups.

Mating structure of an endangered population of wild Atlantic salmon (Salmo salar) as determined using sibship reconstruction and a novel method of sex inference

2012 ◽  
Vol 69 (8) ◽  
pp. 1352-1361 ◽  
Author(s):  
Louise G. de Mestral ◽  
Christophe M. Herbinger ◽  
Patrick T. O’Reilly
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Mature Male ◽  
Bay Of Fundy ◽  
Multilocus Genotype ◽  
Group Level ◽  
Atlantic Salmon Salmo Salar ◽  
Genotype Information ◽  
Novel Method ◽  
Mature Male Parr

The recent development of molecular genetic markers and methods of inferring relatedness among individuals using multilocus genotype information has allowed new insight into mating systems in the wild. Capitalising on the recently discovered linkage between the microsatellite locus Ssa202 and the sex-determining region of the Atlantic salmon Y chromosome, we developed a novel method to infer the sex of unsampled, wild-spawning parents of some of the few remaining wild, inner Bay of Fundy Atlantic salmon ( Salmo salar ). We inferred that most of the unsampled, reconstructed parents at the half-sib group level were likely polygamous females, while the parents at the full-sib group level (nested within half-sib groups) were likely monogamous males. Given the very low numbers of anadromous salmon returning to inner Bay of Fundy rivers to spawn, the putative male parents were likely mature male parr rather than anadromous males. This suggests that salmonid populations experiencing extreme declines may be composed of a high proportion of related individuals from relatively few sib groups and that mature male parr may provide an important genetic and demographic buffer to population decline.

Escalation of an asymmetric contest: mortality resulting from mate competition in Atlantic salmon, Salmo salar

1987 ◽  
Vol 65 (3) ◽  
pp. 766-768 ◽  
Author(s):  
Jeffrey A. Hutchings ◽  
Ransom A. Myers
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Mature Male ◽  
Mate Competition ◽  
Male Aggression ◽  
Dorsal Fin ◽  
Atlantic Salmon Salmo Salar ◽  
Mandibular Teeth ◽  
Mature Male Parr ◽  
Spawning Sites

Male anadromous Atlantic salmon, Salmo salar, fatally injured mature male parr during spawning. The wound consisted of three parallel cuts which exposed musculature on one side of the parr either directly below or immediately posterior to the base of the dorsal fin. The spacing of the cuts matched the spacing of the anadromous male's lingual and mandibular teeth. The wounding of parr in this manner is consistent with the observation of larger males vigorously shaking smaller males between their jaws. Mortality resulting from anadromous male aggression contributes to the low survival of mature male parr. Given the high mortality associated with parr maturation, if male parr must compete with anadromous males and other parr at all spawning sites, parr may be willing to risk escalated contests during mate competition with anadromous males to fertilize eggs.

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