7609

• UCREFRP Catalog Number: 7609
• Author: Hawkins, J. A.
• Title: Age and Growth of Colorado Sqawfish from the Upper Colorado River Basin, 1978-1990.
• USFW Year: 1992.
• USFW - Doc Type: Colorado State University,
• Copyright Material: NO

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TABLE OF CONTENTS

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INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

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Previous studies .......................................... 4

Objectives ............................................... 7

METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

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Capture and tagging records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Weight-length relationship .................................. 11
Fish condition ........................................... 13

Age and growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Back-calculation of length ................................ 17
Age validation ......................................... 18
Relative growth ........................................ 18
von Bertalanffy growth function ............................ 20

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RESULTS AND DISCUSSION ................................... 22

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Capture and tagging records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Length-frequency distributions ............................... 24
Weight-length relationship .................................. 26
Fish condition ........................................... 38

Age and growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Age validation ......................................... 43
Age composition .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Back-calculation of length ................................ 47
Relative growth ........................................ 57
von Bertalanffy growth function ............................ 60

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RECOMMENDATIONS ........................................ 65

SUMMARY.. . . . .,. . . .. ..... ... . . . ...... . . . . . ., . ., . . .. . . . . . .67

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