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Changes in Pigmentation Slress caused by handling or disease can cause blotching, discoloration, and behavioral changes in bony tail. Typically, healthy bony tail school near the bottom of the tank. When bony tail are stressed by some disease or parasite, the sickest fish are generally found by themselves near the surface in a lethargic state. Their bodies are either completely dark or blotched or banded and generally these fish die. The change in coloration can happen quite rapidly. For example, fish were observed hourly during the predator avoidance tank tests. One hour the bony tail appeared and behaved normally; the next hour, one could find a bony tail off by itself in a comer. It would be blotched or totally dark; within the next observation period it might be dead. :rhell' IA ere occasional (( Ii g. I J) Un like the bonytai L we did not experience any losses of these fish; however, their behavior II ~\, ,imibr to the sick bony tail They were often lethargic, avoided schooling, and were often found by them"clvc" We did observe razorback suckers changing color overnight, but the incidence was much '\\ 'I '11.111 1" II~I Lid Thl' l'\~\L'( rL'~\"nn for thi" darker pigmentation or behavioral change is unknown, but ,'.. 'I, I ill ,,'ldl,',1 ((I 'Ill'" \\l' I('und no evidence it led to death. Figure 13. Comparison of a normal colored razorback sucker Itop)with one exhibiting darker pigmentation probably associated with stress. Dl;> !!S~lon 1 , 'i," '1It'd I'll" II 'll' 1,'lll In, l hat predator avoidance is not an inherited trait, but i, ;li"l h ic,1111,'L! III,N'I. 1<)7-1. Olla and Davis. 1989; Magurran, 1990). Our results also agreed with BI()1I1l alld Warburton (1999), who reported that predator-naIve fish are often attracted to predators. CUl'loslty would be a lethal behavioral flaw in the wild. Razorback suckers were found to be naIve to the predators we tested. Our attempts to test bony tail failed due to a chronic outbreak of ich. However, once razorback suckers experienced predatory aggression or a predation event, they exhibited predator avoidance traits. We discovered through recent literature that there are apparent problems of mixing treated and control fish of which we were unaware. Regardless, we found that physical conditioning and prior predator exposure increased the survivability of treatment fish over control fish. All tests were II ilhln the probahility range near p = 0.10, which for fish behavioral studies, is noteworthy. 19