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Table 3. Swimming performance! of bonytail. Average Maximum Minimum Median Total length (mml 181 210 150 185 Control (em/s) 59.98 85.5 17.27 61.23 Control (Bl/sl 3.36 5.0 0.91 3'57 'Trials were limited to 4.5 BLls; resulting averages are conservative. Predation Trials-200G Razorback Suckers The 7-m tank gave prey ample room to escape. Nine trials using 20 razorback suckers ( 10 control and 10 treatment fish) were conducted (Appendix D). Initially, when razorback suckers were released into the tank, they swam franticaJly around and gradually would hide along or inside the shelters with the catfish (fig. 9). In time. they would gradually school and when c1i'lurhl'd "cd II\l' protection of a shelter. All fish would disperse at night. II1cluJlng Ihl' Ildlilcdll 'dlll,11 Initially, each flathead catfish fed about once every four Jays. l3y the end (lllhe Illid". 1111.,,1.11"" were feeding every other night. We recovered the prey fish by parlidlly drainlllg 11lL' 1,111\-' Till" llldl) \ appear to disturb the flathead catfish, which became accustomed to this routine When 11lL' dcr1h held dropped to 10 em, the shelters were placed outside the tank, and the ramrhacK" VlCle dip 11L'I\,'d I Ill' netting generally took less than two minutes. The shelters were immediately replaced. the drain closed. and the tank refilled; a process taking less than one hour. The flathead catfish appeared to become accustomed to this routine as it did not affect their feeding. Figure 9. A school of razorback sucker shown exiting a flathead catfish shelter dUring a predation tr'rl! Fish from both control and treatment groups were attracted to and typically associated With these structures during the initial phase of the test. These structures usually sheltered a large flathead cathsh ]4