The Research On The Pairwise & Triangle Aggressive Interactions And The Application Of Bacillus In Aquaculture Of Procambarus Clarkia

Crayfish Procambarus clarkia has been widely used as a kind of aggressive behavior model animals. The first section of this thesis was focused on the differences between pairwise and triangle interactions in crayfish, the previous research about this segment is still blank. We analyse their agnostic characteristics and variances through observing the aggressive behavior of pairwise and triangle interactions on isodense and equal-area conditions. The short-term trail was set up with pairing group (Pa) and triangle group (Tr), separately observing 20min and 1h. Triangle group was divided into two sections, (Tr1) equidensity with (Pa) and (Tr2) homalographic with (Pa), with the area ratio showed as Spa:Str1:Str2=2:3:2. In long-term test, we severally surveyed the survival rate of equidensity groups (Pa) and (Tr1) for a week. The results show that: 1) the combat of two relationships are mainly concentrated in 10 minutes after a encounter; fight duration per minute of pairwise is significantly greater than triangle’s, fight intensity of each pair in the first 20 min of triangle are significantly lower than that of pairwise. Consequently, fighting intensity of the pairwise interaction is stronger than triangle’s.2) Markedly significant difference in survival rate, fight intensity differences of two interactions have an apparent influence on the outcome of life and death with time lapsing.3) Some studies have shown that crayfish’s combat usually adopts certain strategies, mainly for the hawk strategy and dove strategy. The analysis suggests that pairing relationship assumes "one hawk one dove" strategy, the other utilizes the strategy of "one hawk two doves". As a model animal of agnostic behavior, it’s hard to avoid casualties while crayfish are group housing. In the category of aggressive animals, the comparative results between two agnostic interactions supply some solutions and are of great reference value to reduce fight intensity within groups and obtain small-scale socialized model animals.Procambarus clarkia is best known as a kind of aquatic economic animals. Reasonable cultivation mode can bring economic benefits for aquaculture. At present, the green ecological farming is a hot spot in crayfish aquaculture research, which can increase the production of crayfish, improve the breeding environment and promote the water recycling. In order to study the ecological breeding model of crayfish, the second section of this thesis was centralized in the effects of bacillus subtilis on the anti-heat stress and growth performance in Procambarus clarkia. We added various concentrations of bacillus subtilis bacteria liquids to the aquatic water, comparing differences in biological properties between groups:1) under the condition of high temperature, adding concentration of 2*103cfu already can significantly improve the survival rate, growth rate and antioxidant capacity of juvenile crayfish; 2) under normal temperature condition,8*103cfu is effective to improve the survival rate and growth rate of larval crayfish, which is the optimal effective concentration; 3) 4*103cfu is the minimum effective concentration to enhance the activities of digestive enzymes in juvenile crayfish. Therefore, bacillus subtilis can be applied to the ecological culture of crayfish, enhancing the anti-stress effect, promoting the growth performance, ameliorating the activities of digestive enzymes. Our study provides theoretical references for rational utilization of promoting aquatic animals’healthy breeding with bacillus subtilis.