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Figure 1.4 Depth selection by bonytail in substrate experiments with cobble, with and <br />without red shiners present (low flow). <br />Flow Experiments <br />Three different velocity trials were used (low, medium, high). Flow selection was <br />independent of time of observation (e.g. day versus night) as determined by a one-way <br />ANOVA run for each velocity trial separately (low velocity --p=0.995, medium velocity - <br />p=0.8731 and high velocity - p=0.8064). T-test results comparing nose velocity versus <br />available velocity, for low velocity trials (mean available velocity 0.0336 m/s), suggest <br />that bonytail showed a significant selection for lower velocities of 0.0177 m/s (T=2.36, <br />p=0.0249, df=31; Fig. 1.5). Another T-test was done to compare the nose velocity <br />versus available velocity, for medium velocity trials (mean velocity 0.0589 m/s) and the <br />results indicated that bonytail showed no statistically significant preference for any <br />particular velocity (T=0.82, p=0.4319, df=12; Fig. 1.5). Bonytail were found in flows with <br />a mean velocity of 0.0637 m/s. When a T-test was used to compare the nose velocity <br />versus the available velocity, for high velocity treatments (mean velocity 0.0687 m/s), <br />bonytail again showed no statistically significant preference for any particular flow <br />(T=0.74, p=0.4732, df=12; Fig. 1.5). Interestingly, bonytail were found in flows with a <br />mean velocity of 0.0614 m/s. <br />18