Laserfiche WebLink
<br />Station in Flagstaff, Arizona where they were dissected. Live tapeworms were removed from <br /> <br /> <br />red shiners and inserted down the throat of 108 bonytail (110 - 457 mm total length). These <br /> <br /> <br />bonytail were held for 20 days following infection to allow tapeworms to become established in <br /> <br /> <br />the new hosts. Groups of24 bonytail were then treated with one of 4 dosages ofPraziquantel <br /> <br /> <br />(0.7, 1.5,6.0, and 36.0 mg/L) for two different time durations (12 and 24 hours). Praziquantel <br /> <br /> <br />is soluble in alcohol and only slightly soluble in water So a small volume of 70 % isopropyl <br /> <br /> <br />alcohol was added to the Praziquantel to facilitate mixing (Table 1). Each treatment group had <br /> <br /> <br />an identical control where Praziquantel was not used. Following treatment half of the treated <br /> <br />fish were dissected immediately and the number of tapeworms in each fish was recorded. The <br /> <br />other half of the treated fish were maintained for 30 days to evaluate delayed effects of <br /> <br />Praziquantel use. After 30 days these fish were also dissected and the number of tapeworms <br /> <br />remaining was recorded (Table 2). These laboratory tests were designed to evaluate the dosage <br /> <br />concentration and time requirements to achieve 100 % tapeworm removal from treated fish and <br /> <br />to evaluate methods for quantifying tapeworm loads in individual fish. <br /> <br />Field tests.- Humpback chub were captured in May, 2005 in conjunction with existing <br /> <br />monitoring efforts on the Little Colorado River so as to not subject fish to additional capture <br /> <br />events. A total of 30 humpback chub, that ranged in size from young-of-the-year to adult, were <br /> <br />held for a 24-hour period in a streamside holding tank and treated to remove Asian tapeworm. <br /> <br />All tapeworm treatments occurred near Boulder Camp (RKM 1.9) in the Little Colorado River. <br /> <br />All treated fish were held in a 6-foot diameter portable holding tank (pVC liner on a <br /> <br />collapsible frame) positioned near the stream. The holding tank was filled with 120 gallons of <br /> <br />river water and aerated with battery powered aerators and diffuser tubing. The large volume of <br /> <br />water in the holding tank helped prevent problems with temperature fluctuation and ammonia <br /> <br />buildup during treatment. Fish were treated by placing them individually into perforated <br />