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<br /> <br />Figure 13. An aquarium was set up containing three cover types in an effort to determine <br />the cover preference of 7 -cm bonytail. <br /> <br />pond's depths (3.5 m) to the surface where it formed a large floating mat. Its diameter was <br />approximately 20 m. <br /> <br />We observed more than 100 razorback suckers and 100 bonytail on the morning of 28 July (9 to <br />11 :30 MST). Fish were concentrated in the deeper portions of the pond, especially around and <br />under the shade of the dense column of naiad. All the fish appeared to be using the lower portion <br />of the water column. Razorback suckers were seen solitary and in a large (>50) school (Figures <br />14 and 15). Some were lying stationary in the vegetation while other appeared to be actively <br />feeding along the fringes of the plant growth. Sizes ranged from 30 to 50 cm fish. <br /> <br />Observed bonytail ranged from 7 to 35 cm. Fish were generally swimming alone or in small <br />(<6) groups over or along the fringes of the vegetation. Bonytail appeared to be actively feeding <br />from and on new plant growth. They appeared curious, but stand-offish (<1.5 m) and if the diver <br />made any sudden move, they would dart into the vegetation. <br /> <br />Summary-Cover is obviously an important component ofbonytail habitat. Bonytail are <br />extremely timid and when threatened, will rapidly seek the protection of cover. Large adults <br />appear to be generally nocturnal and fish observed during the day are typically found near cover. <br />Cover undoubtedly provides a means of concealment from avian and other predators. Fish- <br />eating birds such as night herons, great blue herons, common egrets, osprey, pelicans, and <br />cormorants are common around the pond. Small bonytail have been observed taken by <br />kingfishers and the frequency of talon scars suggest large bonytail are also targeted by birds. <br /> <br />Cover at CHLP is diverse and the availability of some types is seasonal. For example, large rip- <br />rap, natural bank cavities and beaver dens provided permanent cavities for fish year-round. We <br />found that large bonytail not only preferred rock . \"'ut individuals used specific cavities <br /> <br />11 <br />