The Trade-off Between Growth And Escape Capability In Qingbo(spinibarbus Sinensis) Under Predator Stress

The predator has a direct impact on the prey of growth and survival in the interspecific relationship. In order to research the imposible trade-off between the fish’s growth and their escape ability under the variable environment of the stress of predator, we identified the exsistence of this possible trade-off and its physiological and behavior mechanism. We set the Spinibarbus sinensis juvenile fish as prey, set Silurus meridionalis as predator. Predation stress group contains control group(without Silurus meridionalis), non-lethal group(Silurus meridionalis and Spinibarbus sinensis apart from each other) and the letal group which let the two fish mixed, to test the trade-off between the growth and escape ability of Spinibarbus sinensis.We also examined the routine metabolic rate(RMR), the maximum metabolic rate(MMR) and metabolic scope(MS) such kind of metabolic parameters; measured the spontaneous movement’s total displacement of moving, the average velocity, movement time percentage and the hidden time percentage such behavioral parameters; response latency detemine, the maximum line velocity(Vmax) and the maximum acceleration(Amax) such quick lunnch parameters. Through the obove experiment research, investigating the influence of variable predation stress treatments have on Spinibarbus sinensis juvenile fish’s growth and escape ability, at the same time to explore the likely physiology and behavior mechanisms of this phenomenon, hope to provide some basal materials related to the physiological ecology of fish.The main findings of this study are as follows:1. There’s no significant fish weight differences between the control groups and treatment groups before treated, while after treatment, the fish weight and the SGR of control grougs are significant higher than the treatment groups(all p<0.05), but the two treatment groups has no difference.2. After treatment, the RMR of lethal group fish obviously higher than that of controlgroups and non-lethal groups(p<0.05), there has no difference between the control groups and the non-lethal groups. Strangely, there has no significant MMR and MS difference in the three groups.3. The response latency of fish in control group is apparently higher than non-lethal group and lethal group(p<0.05), while the non-lethal group and lethal groups’ have no significant difference; nevertheless, Vmax and Amax of this three groups have no differences too.4. The total moving displacement, movement time percentage and the average velocity are clearly higher than that of the control group’s(p<0.05). While the non-lethal group has no significant difference to the other two groups. In addition, the hidden time percentage of control group fish is obviously higher than the remaining groups(p<0.05), there’s no difference between non-lethal and lethal groups.5. The predation rate of control group fish is distincly different from the other two groups(p<0.05), while the later two groups’ predation rate has no remarkable difference.The whole results shows that:1. The routine metabolic rate of prey increased under the pressure of predator, this cause the raising of their energy consumption, leading to the prey who already have been hunted experiences growth inhibited apparently.2. The predation result shows, the been predated rate of experienced prey fish is reduced remarkably as the pressure of predation increases, the survival probability is markedly increased. As the stress of predation increase, the growth of experimental fish has a tendency to decrease slowly. Thus, the balances of Spinibarbus sinensis’ s growth and escape ability is a physiological and behavioral anti-predation strategy under the predation stress environment.3. The Spinibarbus sinensis juvenile fish which have been predated experences are vigilance to be captured by predator because of the shorter response latency and higher routine activity level; however, the vigilance of Spinibarbus sinensis improving and their spontaneous movements lead to higher energy consumption, thereby drops the experienced Spinibarbus sinensis juvenile fish’s growth rate. Under the non-lethal predators stress, fast-start response latency, hidden time’s decrease and spontaneous movement increase are critical important for Spinibarbus sinensis successful escaping.