Developmental rate, fecundity and egg size in Atlantic salmon, Salmo salar L.

Survival, growth, and diet were compared for farmed, hybrid, and wild Atlantic salmon (Salmo salar) families from the eyed egg to the smolt stage in River Guddalselva, Hardangerfjord, Norway. All individuals that survived until the smolt stage were captured in a Wolf trap and identified to one of the 69 experimental families using microsatellite markers. Survival of farmed salmon progeny was significantly lower than that of hybrids and wild progeny. However, survival varied considerably, from 0.17% to 6.4%, among farmed families. Egg size had an important influence on survival. Half-sib hybrid families with a farmed mother had higher survival when fathered by wild salmon than by farmed salmon. The overall relative survival of farmed families compared with that of their hybrid half-sib families fell from 0.86 in the second cohort to 0.62 in the last cohort with increasing fish density. Smolts of farmed parents showed significantly higher growth rates than wild and hybrid smolts. The overlap in diet among types of crosses demonstrates competition, and farm and hybrid progeny therefore will reduce the river’s capacity for production of wild salmon.

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Maintenance of asymmetric hybridization between Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) via postzygotic barriers and paternal effects

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2011-004 ◽

2011 ◽

Vol 68 (4) ◽

pp. 593-602 ◽

Cited By ~ 17

Author(s):

David Álvarez ◽

Eva Garcia-Vazquez

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Brown Trout ◽

Salmo Trutta ◽

Developmental Rate ◽

Paternal Effects ◽

Atlantic Salmon Salmo Salar ◽

Postzygotic Barriers ◽

Brown Trout Salmo Trutta ◽

In The Wild

At the southern European edge of Atlantic salmon ( Salmo salar ) distribution, all the hybrids found in nature are the product of crosses between female salmon and male brown trout ( Salmo trutta ). By artificially producing reciprocal crosses between salmon and trout, we demonstrate that unidirectional hybridization observed in nature is the result of postzygotic barriers that produce very high mortality rates (95%) in female trout × male salmon hybrids and not the consequence of prezygotic isolation or behavioural differences between the two species. Mortality of female trout × male salmon hybrids mainly occurs during the last phases of development, and a high percentage of these surviving hybrids showed external deformities that could compromise survival in the wild. Another important finding is the existence of paternal factor in embryo development. Using time to midhatch as an indicator of developmental rate, female salmon × male trout hybrids hatched faster than female trout × male salmon hybrids, with both developing at a rate intermediate to the pure crosses. The early emergence of female salmon × male trout hybrids, which have similar survival to pure salmons, could have fitness repercussions, since early emerging fry have a competitive advantage over later emerging fry.

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Offspring size effects vary over fine spatio-temporal scales in Atlantic salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2012-0152 ◽

2013 ◽

Vol 70 (1) ◽

pp. 5-12 ◽

Cited By ~ 16

Author(s):

Grethe Robertsen ◽

Helge Skoglund ◽

Sigurd Einum

Keyword(s):

Genetic Variation ◽

Atlantic Salmon ◽

Salmo Salar ◽

Egg Size ◽

Offspring Size ◽

Stabilizing Selection ◽

Atlantic Salmon Salmo Salar ◽

Natural Stream ◽

Spatio Temporal ◽

The Relationship

Classic offspring-size theory predicts that a single level of investment per offspring maximizes parental reproductive success in a given environment. Yet, substantial variation in offspring size is often observed among females within populations. Variation at this scale may occur because spatio-temporal variation in stabilizing selection prevents erosion of genetic variation. We tested whether patterns of size-specific offspring survival of Atlantic salmon (Salmo salar) varies across location and season within a short stretch of a natural stream by manipulating the emergence timing of juveniles from 12 families with different mean egg sizes and assessing their performance at two locations. The relationship between egg size and juvenile survival varied temporally and spatially; large eggs were advantageous for early emergers in one location, whereas egg size had no effect in the other. Furthermore, the performance of later emerging juveniles did not depend on egg size in either location, possibly because the early emergers had grown or established territories. Thus, selection on offspring size can be complex and vary across short periods of time and small geographic distances, thereby preventing the erosion of genetic variation expected under consistent stabilizing selection.

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Precocious Sexual Maturation in Atlantic Salmon (Salmo salar) Postsmolts Reared in a Seawater Impoundment

Journal of the Fisheries Research Board of Canada ◽

10.1139/f78-198 ◽

1978 ◽

Vol 35 (9) ◽

pp. 1269-1272 ◽

Cited By ~ 7

Author(s):

A. M. Sutterlin ◽

P. Harmon ◽

B. Young

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Growth Rates ◽

Egg Size ◽

Sea Water ◽

Early Age ◽

Brood Stock ◽

Atlantic Salmon Salmo Salar ◽

Accelerated Growth ◽

Sexually Mature

Female Atlantic salmon, Salmo salar, usually become sexually mature following a minimum of one winter at sea. Between 4 and 16% maturation was observed for both sexes in two different stocks of salmon placed in sea water as 1+ yr smolts and subsequently reared one summer. Only the larger females and the smaller males matured. Egg size and fertility appeared normal. Smoltification at an early age or accelerated growth rates may be responsible for this phenomenon. Key words: Salinity tolerance, pen-rearing, brood stock, growth rates

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Trans-generational maternal effect: temperature influences egg size of the offspring in Atlantic salmon Salmo salar

Journal of Fish Biology ◽

10.1111/jfb.13040 ◽

2016 ◽

Vol 89 (2) ◽

pp. 1482-1487 ◽

Cited By ~ 17

Author(s):

B. Jonsson ◽

N. Jonsson

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Maternal Effect ◽

Egg Size ◽

Atlantic Salmon Salmo Salar

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Spawning history influence on fecundity, egg size, and egg survival of Atlantic salmon (Salmo salar) from the Miramichi River, New Brunswick, Canada

ICES Journal of Marine Science ◽

10.1093/icesjms/fss091 ◽

2012 ◽

Vol 69 (9) ◽

pp. 1678-1685 ◽

Cited By ~ 18

Author(s):

Jenny E. Reid ◽

Gérald Chaput

Keyword(s):

Body Size ◽

Atlantic Salmon ◽

New Brunswick ◽

Salmo Salar ◽

Egg Size ◽

Positive Association ◽

Egg Survival ◽

Wild Female ◽

Atlantic Salmon Salmo Salar ◽

Egg Diameter

Abstract Reid, J. E., and Chaput, G. 2012. Spawning history influence on fecundity, egg size, and egg survival of Atlantic salmon (Salmo salar) from the Miramichi River, New Brunswick, Canada. – ICES Journal of Marine Science, 69: 1678–1685. There is an increasing abundance of repeat spawners in the Atlantic salmon (Salmo salar) population in the Miramichi River that, owing to their larger size, can be expected to contribute greater egg depositions and better offspring survival than primarily maiden spawning populations. Currently, there is little information on the reproductive contribution of repeat-spawning salmon. In this study, the fecundity, egg size, and egg survival for 235 maiden and repeat-spawning wild female Atlantic salmon were examined over a period of 3 years. Relative fecundity did not differ among the largest body size group of salmon, but consecutive repeat spawners had a higher fecundity than maiden 2SW salmon and alternate repeat spawners. Egg diameter also increased with body size, but consecutive repeat spawners had significantly smaller eggs, in absolute terms and relative to their body size, than maiden 2SW salmon and alternate repeat spawners. The egg survival rate of consecutive repeat spawners was significantly lower than that of 2SW maiden salmon and alternate repeat spawners. Consecutive repeat spawners are different in that egg diameter and egg survival did not follow the general positive association with female body size, probably because of the short time that they spend reconditioning in the ocean and consequently their available energy reserves.

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Potential for domesticated–wild interbreeding to induce maladaptive phenology across multiple populations of wild Atlantic salmon (Salmo salar)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f10-094 ◽

2010 ◽

Vol 67 (11) ◽

pp. 1768-1775 ◽

Cited By ~ 23

Author(s):

Dylan J. Fraser ◽

Cóilín Minto ◽

Anna M. Calvert ◽

James D. Eddington ◽

Jeffrey A. Hutchings

Keyword(s):

Atlantic Salmon ◽

Salmo Salar ◽

Common Garden ◽

Developmental Rate ◽

Wild Populations ◽

Southern Limit ◽

Farmed Salmon ◽

Atlantic Salmon Salmo Salar ◽

In The Wild ◽

Developmental Rates

We report how aquaculture may negatively alter a critical phenological trait (developmental rate) linked to survival in wild fish populations. At the southern limit of the species range in eastern North America, the persistence of small Atlantic salmon ( Salmo salar ) populations may be constrained by interbreeding with farmed salmon that escape regularly from intensive aquaculture facilities. Using a common-garden experimental protocol implemented over an 8-year period, we show that embryos of farmed salmon and multigenerational farmed–wild hybrids (F1, F2, wild backcrosses) had slower developmental rates than those of two regional wild populations. In certain cases, our data suggest that hybrid developmental rates are sufficiently mismatched to prevailing environmental conditions that they would have reduced survival in the wild. This implies that repeated farmed–wild interbreeding could adversely affect wild populations. Our results therefore reaffirm previous recommendations that based on the precautionary principle, improved strategies are needed to prevent, or to substantially minimize, escapes of aquaculture fishes into wild environments.

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