9627 - Laserfiche WebLink

Home Browse Search

vi Ecology of Bonytail and Razorback Sucker 13. Captured bonytail that were held for a few days often exhibited discoloration, swelling, stiffness, and subdermal hemorrhaging .................................................................................12 14. Hatchery bonytail used in an experiment exhibited body discoloration or banding assoc iated with handling ..........................................................................................................13 15. A drawing illustrating the morphology of bonytaillarvae ..............................................................13 16. A photograph showing an intermediate-sized bonytail.................................................................14 17. Gordon Mueller (U.S. Geological Survey) holding a large (50 cm), mature bonytail ................14 18. Two large (>40 cm) bonytails ..............................................................................................................14 19. Historical and current distribution of bonytail in the Colorado River Basin ...............................15 20. Bonytail stomach contents by 50-mm size class, Cibola High Levee Pond ................................16 21. Average length (mm) of bonytail growth of known ages at CHLP and Dexter NFHTC .............16 22. A school of small (>5 cm) bonytail found inside the entrance of a beaver den at Cibola High Levee Pond ..................................................................................................................................17 23. A small bonytail female freely expressing eggs taken from Cibola High Levee Pond ..............18 24. Ripe male bonytail with sexually pigmented coloration ................................................................18 25. Sexual characteristics of female and male bonytail ......................................................................18 26. Hydrograph for the Colorado River at Yuma, Arizona (1904-1934) ...............................................19 27. Bonytail spawning site located on the terminus of a beaver trail on the river levee ...............19 28. Fish activity at Cibola High Levee Pond ............................................................................................20 29. Startled bonytail exhibiting a cooperative fright behavior ............................................................20 30. Drawings of razorback sucker larvae ...............................................................................................21 31. A juvenile razorback sucker about 10 cm in total length ...............................................................21 32. C.O. Minckley holding a repatriated razorback sucker ..................................................................21 33. Photograph showing the sexual characteristics of a razorback sucker female and male showing differences in size and shape of their genitalia ....................................................22 34. Historic and current range of stocked and wild populations of razorback sucker ...................23 35. The abdominal area of a razorback sucker larvae .........................................................................25 36. A school of approximately three dozen adult razorback suckers feeding on zooplankton near the surface of CHLP ...................................................................................................................25 37. Quentin Bradwisch (Utah Department of Natural Resources) with a razorback sucker that was captured by trammel net ..................................................................................................26 38. A high percentage of old razorback suckers were blind in one or both eyes ................................26 39. Comparison of the average length (TL=mm) of razorback sucker year classes grown under different re a ri ng conditions ................... ....................... .......... ...... ..... ................ .............................26 40. A razorback sucker located in the main channel of the Colorado River ..........................................27 41. A juvenile razorback sucker hiding its head in aquatic vegetation .............................................28 42. Swelled genital region of a young razorback sucker female showing expelled eggs ..................28 43. Hydrograph for the Colorado River at Yuma, Arizona ..........................................................................29 44. The last known location (exposed gravel bar between the two islands) where wild razorback sucker spawn in the Green River near Jensen, Utah ................................................................29 45. A diagram of the Ringbolt Rapids spawning site located downstream of Hoover Dam ...............30 46. A photograph showing where razorback suckers spawned at the Ringbolt Rapids site ............30 47. Repatriated razorback suckers migrate possibly 40 km or more upstream from Lake Havasu to spawn nea r Nee dies, Ca lifornia ............ ............ ...... ........... ...................................................... ......30 48. Substrate used by spawning razorback sucker found in the mainstem Colorado River ..............30 49. Thousands of razorback suckers once spawned along the shoreline of the major mainstem reservoirs in the Lower Colorado River ........................................................................................31