Morphological and Early Life History Variation in Salmonid Fishes PDF Download

Author: Susanna Pakkasmaa
Publisher:
ISBN: 9789529117437
Category : Salmonidae
Languages : en
Pages : 108

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Author: Mary F. Willson
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 60

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Author: Mary F. Willson
Publisher: Forgotten Books
ISBN: 9780265016275
Category : Science
Languages : en
Pages : 66

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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.

Author: Andrew P. Hendry
Publisher: Springer Science & Business Media
ISBN: 9401005850
Category : Science
Languages : en
Pages : 528

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From guppies to Galapagos finches and from adaptive landscapes to haldanes, this compilation of contributed works provides reviews, perspectives, theoretical models, statistical developments, and empirical demonstrations exploring the tempo and mode of microevolution on contemporary to geological time scales. New developments, and reviews, of classic and novel empirical systems demonstrate the strength and diversity of evolutionary processes producing biodiversity within species. Perspectives and theoretical insights expand these empirical observations to explore patterns and mechanisms of microevolution, methods for its quantification, and implications for the evolution of biodiversity on other scales. This diverse assemblage of manuscripts is aimed at professionals, graduate students, and advanced undergraduates who desire a timely synthesis of current knowledge, an illustration of exciting new directions, and a springboard for future investigations in the study of microevolution in the wild.

Author: Bror Jonsson
Publisher: Springer Science & Business Media
ISBN: 9400711891
Category : Science
Languages : en
Pages : 720

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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.

Author: R.C. Chambers
Publisher: Springer Science & Business Media
ISBN: 9400914393
Category : Science
Languages : en
Pages : 616

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Book Description
Many of the processes influencing recruitment to an adult fish population or entry into a fishery occur very early in life. The variations in life histories and behaviours of young fish and the selective processes operating on this variation ultimately determine the identities and abundance of survivors. This important volume brings together contributions from many of the world's leading researchers from the field of fish ecology. The book focuses on three major themes of pressing importance in the analysis of the role that the early life history of fishes plays in the number and quality of recruits: the selective processes at play in their early life history; the contributions of early life history to the understanding of recruitment.

Author: W. Pennell
Publisher: Elsevier
ISBN: 0080539661
Category : Science
Languages : en
Pages : 1071

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Book Description
As salmonids have been reared for more than a century in many countries, one might expect that principles are well established and provide a solid foundation for salmonid aquaculture. Indeed, some of the methods used today in salmonid rearing are nearly identical to those employed one hundred years ago. Areas of salmonid research today include nutrition, smolt and stress physiology, genetics and biotechnology. The purpose of this book is to provide a useful synthesis of the biology and culture of salmonid fishes. The important practices in salmonid culture as well as the theory behind them is described. This volume will be of interest to students, researchers, fisheries biologists and managers as well as practising aquaculturists.

Author: Lennart Nyman
Publisher:
ISBN:
Category : Fisheries
Languages : en
Pages : 536

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Author: Laith A. Jawad
Publisher: Springer Nature
ISBN: 3030575705
Category : Science
Languages : en
Pages : 1612

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Book Description
The system of the Tigris-Euphrates Rivers is one of the great river systems of southwestern Asia. It comprises the Tigris and Euphrates Rivers, which follow roughly parallel courses through the heart of the Middle East. The lower portion of the region that they run through is known as Mesopotamia, was one of the cradles of civilisation. There are several environmental factors that govern the nature of the two rivers and shape the landscape the two rivers running through. Geological events create rivers, climate monitor the water supply, the surrounding land influences the vegetation and the physical and chemical features of water. The Tigris-Euphrates system runs through the territory of four countries, Iraq, Iran, Turkey and Syria. Therefore, any scientific approach to the environment of these two rivers should include the natural history events in these countries. The book "Tigris and Euphrates Rivers: Their Environment from Headwaters to Mouth" will be divided into nine parts. These parts deal with the issues of the environment, the status of the flora and fauna, the abiotic aspects, ecology, hydrological regime of the two rivers, the biotic aspects. Water resources, stress of the environment, conservation issues. Since the book of Julian Rzoska "Euphrates and Tigris Mesopotamian Ecology and Destiny" in 1980, no book or major reference has been published that includes between its cover the facts and information that the present book will present. Therefore, the importance of the present book falls in stating the present status of the environment of the two rivers and the comparison of their environment between now and that of 37 years ago as given by J. Rzoska (1980). The recent studies showed that there are a large number of natural and political events that happened within the last three decades in the area of the Tigris-Euphrates river system that for sure have done a great change to the environment of the two rivers and consequently changing the biological and non-biological resources of the two rivers. This book will be a reference book to both Academic and students across the Middle East in different disciplines of knowledge to use in their researches on Tigris-Euphrates river system. The scholars interested in this area will use this book as a guide to compare this freshwater system with other areas in Asia and the world.

Author:
Publisher:
ISBN:
Category : Fisheries
Languages : en
Pages : 436

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