养殖密度、断食时长和优势等级对克氏原螯虾摄食行为的影响

Effects of Stocking Density,Feed Deprivation Duration and Dominance Hierarchies on Feeding Behavior of Procambarus clarkii

为深入理解克氏原螯虾(Procambarus clarkii)摄食行为受养殖条件影响的作用机制,本研究围绕养殖密度、断食时长以及群体内个体优势等级3个关键因素,通过对比实验探讨养殖条件关键影响因素如何协同作用,进而优化克氏原螯虾的养殖密度及投喂频次。研究选取初始体重为(9.53±1.45)g、雌雄比例相同的克氏原螯虾,围绕3个关键因素,对克氏原螯虾的摄食行为进行了比较研究。研究结果表明:(1)同等规格雄虾比雌虾的优势等级更高,易成为优势虾,优势虾确立等级行为优先于摄食行为,从属虾一般先于优势虾摄食,且摄食时长显著高于优势虾(P<0.05);(2)投喂饲料会显著提高克氏原螯虾因争食引起的打斗次数(P<0.001),饲料消耗率和饲料吸引力随密度和断食时长的增加而增加;(3)随着养殖密度增加和断食时间的延长,克氏原螯虾的摄食时长、饲料吸引力以及消耗率都显著增高;打斗次数呈现先上升后下降的趋势,且同等条件下优势虾血淋巴中的乳酸含量低于从属虾,反映了个体优势等级在代谢能量分配上的差异。综上,本研究揭示了密度、投喂及优势等级对克氏原螯虾摄食行为的影响,结果对优化克氏原螯虾的养殖管理具有重要指导意义。

To gain a deeper understanding of the key factors influencing the feeding behavior of Procambarus clarkii,this study focused on three critical factors of aquaculture condition—stocking density,feed deprivation,and dominance hierarchy.Through comparative experiments,we chose the P.clarkii with an initial body net weight of(9.53±1.45)g and an equal sex ratio.Furthermore,we explored how these key factors interact synergistically to optimize and clarify the appropriate stocking density and feeding frequency for P.clarkii.The results showed that:(1)males of the same size have a higher dominance rank than females and are more likely to become dominant.The dominant individuals prefer to establish their hierarchy prior to catch food,while subordinate shrimps generally prefer the food first with a significantly longer feeding duration(P<0.05);(2)the input of feeding powders significantly increase the frequency of fights over food(P<0.001).The fighting behavior is increasing with stocking density and feed deprivation;(3)the feeding duration,attractiveness of feed,and consumption rate of P.clarkii significantly increase when increasing the stocking density and feeding duration.Unexpectedly,the number of fights first rises first and then decrease with the lactate expression in hemolymph of dominant shrimps lower than that of subordinate ones,corresponding to the different energy allocation during the metabolism of individual dominant hierarchy.In summary,this study revealed the effects of density,feeding,and dominance level on the feeding behavior of crayfish,which has important guiding significance for optimizing the aquaculture management of crayfish.