Abstract
In 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 per cent, with individual parr fertilizing up to 26 per cent 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.
Keywords: Reproductive Success Density Effects Dna Profiling Salmo Salmar Size Effects Status
Full Text
The Full Text of this article is available as a PDF (329.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Burke T., Bruford M. W. DNA fingerprinting in birds. Nature. 1987 May 14;327(6118):149–152. doi: 10.1038/327149a0. [DOI] [PubMed] [Google Scholar]
- McNamara J. M., Houston A. I. State-dependent life histories. Nature. 1996 Mar 21;380(6571):215–221. doi: 10.1038/380215a0. [DOI] [PubMed] [Google Scholar]
- Wetton J. H., Carter R. E., Parkin D. T., Walters D. Demographic study of a wild house sparrow population by DNA fingerprinting. Nature. 1987 May 14;327(6118):147–149. doi: 10.1038/327147a0. [DOI] [PubMed] [Google Scholar]