Pacific Salmon Life Histories
Pacific Salmon Life Histories

Author: Cornelis Groot

Publisher: UBC Press

Published: 1991

Total Pages: 602

ISBN-13: 9780774803595

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Pacific salmon are an important biological and economic resource of countries of the North Pacific rim. They are also a unique group of fish possessing unusually complex life histories. There are seven species of Pacific salmon, five occurring on both the North American and Asian continents (sockeye, pink, chum, chinook, and coho) and two (masu and amago) only in Asia. The life cycle of the Pacific salmon begins in the autumn when the adult female deposits eggs that are fertilized in gravel beds in rivers or lakes. The young emerge from the gravel the following spring and will either migrate immediately to salt water or spend one or more years in a river or lake before migrating. Migrations in the ocean are extensive during the feeding and growing phase, covering thousands of kilometres. After one or more years the maturing adults find their way back to their home river, returning to their ancestral breeding grounds to spawn. They die after spawning and the eggs in the gravel signify a new cycle. Upon this theme Pacific salmon have developed many variations, both between as well as within species. Pacific Salmon Life Histories provides detailed descriptions of the different life phases through which each of the seven species passes. Each chapter is written by a scientist who has spent years studying and observing a particular species of salmon. Some of the topics covered are geographic distribution, transplants, freshwater life, ocean life, development, growth, feeding, diet, migration, and spawning behaviour. The text is richly supplemented by numerous maps, illustrations, colour plates, and tables and there is a detailed general index, as well as a useful geographical index.

Variation in Salmonid Life Histories
Variation in Salmonid Life Histories

Author: Mary F. Willson

Publisher: DIANE Publishing Company

Published: 1999-09-01

Total Pages: 50

ISBN-13: 9780788179945

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Because of the huge natural variations in the abundance of salmon from year to year and place to place, much of the attention to these species has been prompted by an interest in reducing the variation and simultaneously maintaining or raising the mean abundance. In contrast, the importance of salmon and their relatives to the ecology of other species dependent on them and to the ecology of riparian ecosystems has scarcely been noticed. This review summarizes variation in salmonid life history, with an emphasis on the salmonine lineage, and suggests ecological, evolutionary, and management implications. Tables.

Variation in Salmonid Life Histories, Patterns and Perspectives (Classic Reprint)
Variation in Salmonid Life Histories, Patterns and Perspectives (Classic Reprint)

Author: Mary F. Willson

Publisher: Forgotten Books

Published: 2019-01-02

Total Pages: 66

ISBN-13: 9780265016275

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Excerpt from Variation in Salmonid Life Histories, Patterns and Perspectives Salmonid fishes differ in degree of anadromy, age of maturation, frequency of reproduction, body size and fecundity, sexual dimorphism, breeding season, morphology, and to a lesser degree, parental care. The advantages of large body size in reproductive competition probably favored the evolution of ocean foraging, and the advantages of safe breeding sites probably favored freshwater spawning. Both long-distance migrations and reproductive competition may have favored the evolution of semelparity. Reproductive competition has favored the evolution of secondary sexual characters, alternative mating tactics, and probably nest-defense behavior. Salmonids provide good examples of character divergence in response to ecological release and of parallel evolution. The great phenotypic plasticity of these fishes may facilitate speciation. Patterns of variation and the processes that generate them are valuable tools for foresighted management practices, predicting the outcomes of anthopogenic changes, managing to maintain biodiversity or particular populations of wildlife consumers, and maintaining the viability of fish populations. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Ecology of Atlantic Salmon and Brown Trout
Ecology of Atlantic Salmon and Brown Trout

Author: Bror Jonsson

Publisher: Springer Science & Business Media

Published: 2011-05-03

Total Pages: 720

ISBN-13: 9400711891

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Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.

Evolution Illuminated
Evolution Illuminated

Author: Andrew P. Hendry

Publisher: Oxford University Press, USA

Published: 2004

Total Pages: 521

ISBN-13: 019514385X

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This work gives a critical overview on the evolution and population biology of salmon and their relatives. It should appeal to investigators in each of the scientific disciplines it integrates - evolutionary biology, ecology, salmonid biology, management and conservation. Variation in salmonids can be used to illustrate virtually all evolution.

Life History Variation in Migratory Salmonid Populations
Life History Variation in Migratory Salmonid Populations

Author:

Publisher:

Published: 2020

Total Pages:

ISBN-13:

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Abstract : Over the last 150 years, many of the native migratory salmonid populations in North America have declined or been extirpated, and their native habitats have been significantly altered. Life history variation within and among migratory fish populations plays an important role in their persistence when faced with changing habitat conditions. One of the most extreme life history events in salmonids is the movement from lotic to lentic habitats, a migration that can span long distances and different habitat types. Understanding the factors affecting migratory life histories expressed by individuals within a population play an important role in dynamics and habitat requirements of the whole population. Here, I investigate three primary factors that contribute to an individual fishes' "decision" to migrate: genetics, environmental conditions, and individual body condition. In rainbow trout Oncorhynchus mykiss of the Shasta River, California we found distinct genetic structure among subpopulations in spatially separate habitats. Within one of those population segments we detected partial migration in which some individuals migrate, but others do not. We found that increased in daily mean water temperature were associated with upriver migration of adult coaster brook trout Salvelinus fontinalis in the Salmon Trout River, Michigan. In the Pilgrim River, Michigan we documented a previously unrecognized population of migratory brook trout. These results provide information critical to understanding the ecology of these at-risk populations and broaden our understanding of migratory behavior in general. The methodologies we developed to quantify movement data in the context of migratory life histories are applicable to other systems where further understanding of the drivers of migratory life history variation is needed.