Evol Ecol Res 4: 537-549 (2002)     Full PDF if your library subscribes.

The influence of male parental identity on growth and survival of offspring in Atlantic salmon (Salmo salar)

Dany Garant,¹ Pierre-Michel Fontaine,² Shawn P. Good,³ Julian J. Dodson¹* and Louis Bernatchez¹

¹Département de biologie, Université Laval, Ste-Foy, Québec G1K 7P4, Canada, ²Fédération québécoise pour le salmon atlantique, 42B rue Racine, Loretteville, Québec G2B 1C6, Canada and ³Vermont Department of Fish and Wildlife, Pittsford District Office, 317 Sanitorium Road, Pittsford, VT 05763-9358, USA

Author to whom all correspondence should be addressed.
e-mail: julian.dodson@bio.ulaval.ca

ABSTRACT

We found that young salmon fathered by precocious males grew faster than those fathered by anadromous males in Atlantic salmon (Salmo salar L.) during the time from hatching to yolk sac absorption, when the young are completely dependent on endogenous food resources. We first compared growth rate of artificially reared progeny of precocious and anadromous fish harvested as embryos directly on spawning grounds after reproduction. In a second experiment, we compared fish lengths and growth rate of offspring of precocious and anadromous fish that were caught before reproduction, artificially bred and reared in situ. The first experiment revealed that the progeny of precocious males had a significantly higher growth rate between hatching and yolk sac absorption, resulting in a larger body size, than anadromous offspring. In the second study, we found no significant differences in size between the two groups at any time during the experiment, which could be explained by the artificially enhanced reproductive success of potential subordinate males. Indeed, in the second experiment, the microsatellite analysis of paternal identity revealed that precocious males who fathered the most progeny had offspring with a larger mean size throughout the experiment, resulting in a marginally significant difference in length between precocious offspring and anadromous offspring. A higher but not significantly different mortality rate was also observed in anadromous than in precocious offspring throughout the second experiment. Our results indicate an inherent fitness advantage in some offspring fathered by precocious males, which may ultimately favour the development of precocious sexual maturity in Atlantic salmon.

Keywords: alternative reproductive tactics, conditional strategy, fertilization success, growth rate, Salmonidae.

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        © 2002 Julian J. Dodson. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

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