Effects of insect herbivory on early plant succession: comparison of an English site and an American site |
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Authors: | STEPHEN D. HENDRIX VALERIE K. BROWN ALAN C. GANGE |
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Affiliation: | Department of Zoology, University of Montana, Missoula, Montana 59812, U.S.A. |
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Abstract: | We examined the survival, size, and agonistic behaviour of faster and slower developing rainbow trout ( Salmo gairdneri ) in an artificial stream channel with a simulated redd. The analysis was performed at two levels: between three full-sib families genetically marked at a hexosaminidase locus, and within families segregating for a regulatory allele Pgml-t(b) that is associated with faster developmental rate. The families differed significantly in their hatching times but showed little variation in emergence times. Fishes with the Pgml-t(b) allele hatched and emerged significantly earlier than their full-sibs without the allele. Despite the mortality of at least 50% of emerged fishes in the selection experiment, there was no significant difference in survival between either the three families or fishes with different genotypes at the Pgml-t locus. However, fishes from the faster developing family and those with the Pgml-t(b) allele had significantly higher levels of agonistic behaviour and had a tendency to be larger than slower developing individuals. |
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Keywords: | regulatory gene survival selection competition agonistic behaviour size emergence hatching Salmonidae |
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