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7 <br />STOCKING: Davis Cove received approximately 10,000 juvenile razorback <br />suckers from Dexter National Fish Hatchery on June 24, 1992. The fish were <br />monitored weekly by USBR and ASU. The fish averaged 68 mm in length <br />upon stocking and increased to 128 mm by September, almost doubling their <br />size (Table 2). <br />BEHAVIOR: Indirect evidence through seining and trapping, along with <br />direct observations through snorkeling and SCUBA showed the young fish <br />were nocturnal. One mystery surrounding this species is why they are so <br />susceptible to predation when they evolved in a system with a top fish <br />predator, the Colorado squawfish. The young razorback suckers hide out <br />during the day in nooks, caves, under brush and in weeds, which are all <br />presently occupied by turtles, crayfish and catfish, making the young suckers <br />easy prey for these organisms. Preliminary observations in Davis Cove <br />suggest at night they are normally associated with sandy substrates bordered <br />by dense vegetation. Suckers appear well distributed throughout the cove <br />after dark regardless of water depth (1-30 ft). <br /> <br />w <br />PREDATION: During weekly monitoring in Davis Cove, efforts continued to <br />remove unwanted gamefish. Predation by largemouth bass was observed but <br />the extent of the pressure-is still unknown (but suspected to be high). One <br />significant observation through the summer and fall was the tremendous <br />crayfish population that developed following removal of most of the <br />largemouth bass. By October it was common to capture 5 - 10 crayfish in <br />each 150 foot trammel net set over night. The crayfish fed upon both native <br />and non-native fish entangled in the net. <br />LJ