Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).

In this thesis I looked at the choice of mating tactics in male Atlantic salmon by determining the fertilisation success of individuals adopting different mating behaviours. In this species, as in most salmonids, males can either become sexually mature early in the life cycle, as small freshwater ju...

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Main Author: Thomaz, Diogo Miguel Pereira Fernandes.
Format: Doctoral or Postdoctoral Thesis
Language:English
Published: College of Medicine, Biological Sciences and Psychology 2015
Subjects:
Online Access:http://hdl.handle.net/2381/34249
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spelling ftleicester:oai:lra.le.ac.uk:2381/34249 2023-05-15T15:31:07+02:00 Alternative life-history strategies in male Atlantic salmon (Salmo salar L.). Thomaz, Diogo Miguel Pereira Fernandes. 2015-11-19T08:51:21Z http://hdl.handle.net/2381/34249 en eng College of Medicine, Biological Sciences and Psychology University of Leicester http://hdl.handle.net/2381/34249 U073043 x753138807 Copyright © the author. All rights reserved. ProQuest Doctoral Ph.D. 2015 ftleicester 2019-03-22T20:20:48Z In this thesis I looked at the choice of mating tactics in male Atlantic salmon by determining the fertilisation success of individuals adopting different mating behaviours. In this species, as in most salmonids, males can either become sexually mature early in the life cycle, as small freshwater juveniles called parr, or undergo a sea migration before maturing. The alternative behaviours are thought to be contingent on environmental and social circumstances, although some researchers see them as mixed evolutionarily stable strategies. Here, using the charomid cloning method I isolated eight highly polymorphic minisatellite DNA markers and, using two that showed heterozygosities above 80%, fingerprinted more than 2,000 salmon embryos and measured for the first time the fertilisation success of mature parr and anadromous males in a wild Scottish population. The percentage of eggs fertilised by mature parr was estimated to be between 35% and 40% in this population, more than double the two previous estimates reported in semi-natural environments. In mating experiments in captivity I manipulated the number and body size of parr. Pairs of migrants were allowed to spawn in an enclosure with mature parr. Analysis of paternity revealed a strong correlation (r2=0.95) between parr size and reproductive success. The results also provided further support to a hypothesis predicting negative frequency dependent reproductive success in this species. The results in both the experiments and the field study are used to develop an optimisation model for understanding life history variation in this species. The model assumes that the choice of mating tactics is contingent on body size. General agreement between the results and observations in wild populations is taken as supportive of the important role that environment plays in male mating tactic choice in Atlantic salmon. Doctoral or Postdoctoral Thesis Atlantic salmon Salmo salar University of Leicester: Leicester Research Archive (LRA)
institution Open Polar
collection University of Leicester: Leicester Research Archive (LRA)
op_collection_id ftleicester
language English
description In this thesis I looked at the choice of mating tactics in male Atlantic salmon by determining the fertilisation success of individuals adopting different mating behaviours. In this species, as in most salmonids, males can either become sexually mature early in the life cycle, as small freshwater juveniles called parr, or undergo a sea migration before maturing. The alternative behaviours are thought to be contingent on environmental and social circumstances, although some researchers see them as mixed evolutionarily stable strategies. Here, using the charomid cloning method I isolated eight highly polymorphic minisatellite DNA markers and, using two that showed heterozygosities above 80%, fingerprinted more than 2,000 salmon embryos and measured for the first time the fertilisation success of mature parr and anadromous males in a wild Scottish population. The percentage of eggs fertilised by mature parr was estimated to be between 35% and 40% in this population, more than double the two previous estimates reported in semi-natural environments. In mating experiments in captivity I manipulated the number and body size of parr. Pairs of migrants were allowed to spawn in an enclosure with mature parr. Analysis of paternity revealed a strong correlation (r2=0.95) between parr size and reproductive success. The results also provided further support to a hypothesis predicting negative frequency dependent reproductive success in this species. The results in both the experiments and the field study are used to develop an optimisation model for understanding life history variation in this species. The model assumes that the choice of mating tactics is contingent on body size. General agreement between the results and observations in wild populations is taken as supportive of the important role that environment plays in male mating tactic choice in Atlantic salmon.
format Doctoral or Postdoctoral Thesis
author Thomaz, Diogo Miguel Pereira Fernandes.
spellingShingle Thomaz, Diogo Miguel Pereira Fernandes.
Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).
author_facet Thomaz, Diogo Miguel Pereira Fernandes.
author_sort Thomaz, Diogo Miguel Pereira Fernandes.
title Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).
title_short Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).
title_full Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).
title_fullStr Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).
title_full_unstemmed Alternative life-history strategies in male Atlantic salmon (Salmo salar L.).
title_sort alternative life-history strategies in male atlantic salmon (salmo salar l.).
publisher College of Medicine, Biological Sciences and Psychology
publishDate 2015
url http://hdl.handle.net/2381/34249
genre Atlantic salmon
Salmo salar
genre_facet Atlantic salmon
Salmo salar
op_source ProQuest
op_relation http://hdl.handle.net/2381/34249
U073043
x753138807
op_rights Copyright © the author. All rights reserved.
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