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<br />o <br />o <br />o <br />~ <br />. <br /> <br />. <br /> <br />. <br /> <br />Hatchery (from the current Dexter NFH brood stock) and presently held at Dexter <br />National Fish Hatchery and Teclmology Center will be used for this study segment. <br />During fall 1991, experimental fish will have the posterior attachment sites for <br />ovaries and testes severed and ends of gonads sutured, tied closed, and <br />cauterized. Experimental and control fish will be held overwinter in a <br />recirculating raceway system at Willow Beach NFH to provide current conditioning <br />and fed live rainbow trout to simulate a more natural diet. Experimental fish <br />will be anesthetized, gonads exposed and examined for condition (maturation) and <br />physical status af previous surgery, and if incapable of reproducing, recovered <br />and maintained in the raceway system for potential future use. Whether or not <br />these experimental fish would be used for telemetry studies would be dependent <br />upon the numbers of wild adult Colorado squawfish collected during fall 1991 and <br />spring/summer 1992 in the San Juan River. The experimental fish will continue <br />to be held at Willow Beach NFH in the manner described above for as long as a <br />potential need exists. <br /> <br />Excerimental Desian- Colorado Sauawfish Neuterina <br /> <br />I. Acquisition of experimental and control fish <br />Thirty 1981 year class held at DNFH transported to WBNFH October 1991 <br />Fish separated into two raceways with current and fed a diet (amount to <br />be determined) of live rainbow trout <br />Raceway system is two concrete raceways set in tandem with a <br />recirculating pump on each end and adjusted so that flow is circulated <br />from the upper end of raceway No. 1 to the lower end and pumped into <br />raceway No. 2 where the water is pumped at the upper end of No. 2 into <br />No. l. <br />Rainbow trout are reared at the hatchery available on site for <br />systematic feeding. <br /> <br />A. Control fish <br />- 12 fish total, 6 male and 6 female <br />- placed in raceway No. 1 <br /> <br />B. Experimental fish <br />12 'f ish total, 6 male and 6 female <br />- placed in raceway No. 2 <br /> <br />C. Backup fish <br />- 6 remaining fish held in sep~rate raceway <br /> <br />II. Holding/maintenance of fish <br />A. Establishment and maintenance of above described raceway system <br /> <br />B. <br /> <br />Feeding <br />- live hatchery-reared <br />- feeding rate is <br /> <br />rainbow 'trout <br />kg of trout/kg live weight of CSF <br /> <br />C. Fish held for 30 days in above system prior to surgery <br />III. Physical data acquisition, Surgery <br /> <br />A. <br /> <br />Length/weight data collected for all individuals <br />- TL, SL, WEIGHT, EXTERNAL APPEARANCE <br /> <br />B. <br /> <br />Surgery <br />anesthetize fish, follow identical surgery maintenance procedures <br />as established for implanting radio transmitters <br />- incision ventro-Iaterally from slightly anterior of pelvic girdle to <br />near vent <br /> <br />A1S <br />