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<br />:JJ2'748 <br /> <br />broodstocks. The lack of sufficient adult fish has resulted in the application of different spawning <br />matrices for each species. <br /> <br />Colorado squawflsh: Initial development of Colorado squawfish broodstock took place at Dexter <br />National Fish Hatchery (NFH), New Mexico. From a total of 10 adult squawfish taken from the <br />Upper Colorado River upstream of Westwater Canyon, a total of 18 family lots were spawned at <br />Dexter in 1991 using a di-allele 5 x 5 breeding matrix. The development ofa broodstock using a <br />breeding matrix of25 paired matings is "on hold" due to lack of facilities. Available propagation <br />facilities are in use developing the two razorback sucker brood stocks that are considered by the <br />Recovery Program to be a higher priority. No broodstock have been developed for the other <br />presumptive stocks (Yarnpa, Desolation-Gray Canyon, Gunnison). Currently. the primary refuge for <br />Colorado squawfish is located at Dexter NFH while facilities at Horsethief State Wildlife Area/Grand <br />Valley Endangered Fish Facility (Horsethief) serve as a backup refuge. <br /> <br />Bony tail chub: The development ofbonytail chub broodstock began in 1994 when 25 family lots of <br />fertilized eggs were produced at Dexter NFH. Unfortunately, transfer of these eggs to Valley City <br />National Fish Hatchery in North Dakota was delayed due to inclement weather, resulting in the <br />successful hatching of only three lots. One additional lot was spawned at Dexter that year and <br />transferred to Valley City. The four lots of fish were reared at Valley City and transferred to <br />Horsethief SWAin November, 1994. No additional development ofbonytail broodstock has taken <br />place since initial efforts in 1994, given the lack of facilities and the higher priority of the razorback <br />sucker. Currently,S adult bonytail are being held in refuge at Horsethief, along with four family lots <br />produced at Dexter NFH. Horsethief will remain a backup refuge for bonytail chub, with the primary <br />refuge located at Dexter NFH. <br /> <br />Humpback chub: Regarding humpback chub broodstock development, in 1995, 15 adult humpback <br />chubs were captured from the Black Rocks area and were placed in a 0.25 acre pond at Horsethief <br />SW A These fish are being maintained at Horsethief to prevent the possibility of catastrophic <br />extinction. No further development of brood stock at Horsethief is occurring or planned. No <br />brood stock have been developed for other presumptive stocks of humpback chubs (Yampa, <br />Desolation-Gray Canyon, Cataract Canyon, Westwater Canyon). <br /> <br />Razorback sucker: At the Ouray Endangered Fish Culture Experiment Station (EFCES), the <br />broodstock for Middle Green River razorback sucker is being developed at Ouray EFCES in Utah. <br />Through the end of 1996, Ouray has produced 4 of the 25 required lots requested under the 25 mated <br />pair genetics plan. Development of Middle Green River razorback sucker brood stock at Ouray <br />during FY 1997 will be limited to no more than 6-8 family lots, due to the lack of intensive culture <br />facilities and limited pond space. The need for a backup refugia still exists and would alleviate some <br />of the space requirements at Ouray. Facilities at Wahweap SFH are likely to serve as the backup <br />refuge for the Middle Green razorback sucker. No broodstock are being developed from the Yampa <br />presumptive stock. <br /> <br />An excessive demand is being placed on the facilities at Ouray due to (1) contribution offish from <br />various areas requiring space for captivity and culture, (2) increasing size of the fish, and (3) limited <br />release to the wild. This continuous demand on space has resulted in caring for more fish than the <br />facility, at its current capacity, can handle. Fish held at too high a density are more vulnerable when <br /> <br />IV <br />