DESCRIPTION AND IDENTIFICATION OF JUNE, UTAH, AND MOUNTAIN SUCKER LARVAE AND EARLY JUVENILES by Darrel E. Snyder and Robert T. Muth Publication No. 88-8 STATE OF UTAH NATURAL RESOURCES k) Wildlife Resources DESCRIPTION AND IDENTIFICATION OF JUNE, UTAH, AND MOUNTAIN SUCKER LARVAE AND EARLY JUVENILES by Darrel E. Snyder and Robert T. Muth Larval Fish Laboratory Colorado State University Fort Collins, Colorado 80523 Contribution 37 of the Larval Fish Laboratory, Colorado State University July 1988 Utah State Division of Wildlife Resources Contract 87-2891 Utah State Division of Wildlife Resources 1596 West North Temple Salt Lake City, Utah 84116-3154 88-8 CONTENTS LIST OF TABLES ................................................................................................................................................. iii LIST OF FIGURES ......................................................................................................................................... iv ACKNOWLEDGEMENTS ............................................................................................................................. vi ABSTRACT ..................................................................................................................................................... 1 INTRODUCTION ............................................................................................................................................. 2 A COMBINED DEVELOPMENTAL INTERVAL TERMINOLOGY ............................................ 4 CHARACTERISTICS USEFUL IN IDENTIFICATION OF CYPRINIFORM LARVAE . 6 Myomeres ................................................................................................................................................. 7 Fins and Finfolds .......9 Other Countable Structures ................................................................................................................. 11 Morphology ............................................................................................................................................. 11 Pigmentation ............................................................................................................................................. 13 Osteology ................................................................................................................................................. 14 SPECIMENS EXAMINED ............................................................................................................................. 15 METHODS ......................................................................................................................................................... 16 Specimen Data and Observations ......................................................................................................... 16 Clearing and Staining Procedures ..................................................................................................... 20 RESULTS AND CONCLUSIONS ............................................................................................................. 22 Comparative Summary ......................................................................................................................... 22 Keys ......................................................................................................................................................... 29 Species Account -- Chasmistes liorus ............................................................................................. 46 Species Account -- Catostomus ardens ......................................................................................... 54 Species Account -- Catostomus platvrhynchus ............................................................................. 62 LITERATURE CITED ................................................................................................................................. 70 APPENDIX A, INDIVIDUAL MEASURES AND COUNTS ............................................................. 75 APPENDIX B, COMPARATIVE GRAPHS OF MORPHOMETRIC DATA ................................ 85 APPENDIX C, GROWTH CURVES FOR REARED SPECIMENS ................................................. 104 ii LIST OF TABLES 1 Comparison of . useful differences in size relative to state of development ................ 23 2 Comparison of diagnostically useful differences in meristics and morphometrics 24 3 Selected juvenile and adult meristics for Chasmistes liorus ................................................ 46 4 Size at apparent onset of selected developmental events for Catostomus liorus ............... 46 5 Size at developmental interval and gut phase transitions for Chasmistes liorus ............... 47 6 Summary of morphometrics and myomere counts . for Chasmistes liorus .................. 47 7 Frontoparietal fontanelle dimensions for Chasmistes liorus ................................................ 53 8 Selected juvenile and adult meristics for Catostomus ardens ................................................ 54 9 Size at apparent onset of selected developmental events for Catostomus ardens ............... 54 10 Size at developmental interval and gut phase transitions for Catostomus ardens ............... 55 11 Summary of morphometrics and myomere counts . for Catostomus ardens .................. 55 12 Frontoparietal fontanelle dimensions for Catostomus ardens ................................................ 61 13 Selected juvenile and adult meristics for Catostomus platyrhynchus ................................. 62 14 Size at apparent onset of selected developmental events for C. platvrhynchus. ............... 62 15 Size at developmental interval and gut phase transitions for C. platvrhynchus ............... 63 16 Summary of morphometrics and myomere counts . for Catostomus platvrhynchus 63 17 Frontoparietal fontanelle dimensions for Catostomus platvrhynchus ................................. 69 Appendix Tables Appendix A. Individual Measures and Counts for Fully Analyzed Specimens A-1 Individual measures and counts for . Chasmistes liorus . reared ................................ 76 A-2 Individual measures and counts for . Catostomus ardens . reared ............................ 79 A-3 Individual measures and counts for . Catostomus platvrhynchus . reared ................ 82 A-4 Individual measures and counts for . Catostomus platyrhvnchus . captured . 83 iii LIST OF FIGURES 1 Selected anatomical features of catostomid fish eggs and embryos ......................................... 7 2 Selected anatomical features of catostomid fish larvae................................................................. 8 3 Measures and counts for larval and early juvenile fishes ......................................................... 17 4 Phases of gut coil development in catostomid fish larvae and early juveniles .................... 18 5 Location of selected skeletal features of metalarval and early-juvenile catostomids . 19 6 Chasmistes liorus, adult ......................................................................................................................... 46 7 Distribution of Chasmistes liorus. ..................................................................................................... 46 8 Chasmistes liorus protolarva, recently hatched ............................................................................. 48 9 Chasmistes liorus protolarva ................................................................................................................. 48 10 Chasmistes liorus flexion mesolarva, recently transformed ......................................................... 49 11 Chasmistes liorus postflexion mesolarva ......................................................................................... 49 12 Chasmistes liorus metalarva, recently transformed ..................................................................... 50 13 Chasmistes liorus metalarva ................................................................................................................. 50 14 Chasmistes liorus juvenile, recently transformed ......................................................................... 51 15 Chasmistes liorus juvenile ..................................................................................................................... 51 16 Selected diagnostic skeletal features of Chasmistes liorus . 25.6 mm TL ........................ 52 17 Selected diagnostic skeletal features of Chasmistes liorus . 45 mm TL ............................ 52 18 Interneurals of Chasmistes liorus ......................................................................................................... 53 19 Frontoparietal fontanelle of Chasmistes liorus ............................................................................. 53 20 Catostomus ardens, adult ..................................................................................................................... 54 21 Regional distribution of Catostomus ardens ..................................................................................... 54 22 Catostomus ardens protolarva, recently hatched ............................................................................. 56 23 Catostomus ardens protolarva ............................................................................................................. 56 24 Catostomus ardens flexion mesolarva, recently transformed ....................................................