温度对克氏原螯虾摄食、生长、酶活性及肠道菌群的影响OA

To investigate the effects of temperature on the feeding,growth,enzyme activity,and intestinal microbiota of the red swamp crayfish(Procambarus clarkii),juveniles with an average weight of(3.80±0.05) g were selected and subjected to four temperature treatments(15℃,20℃,25℃,and 30℃).The results indicated that both daily feed intake and daily feeding rate increased with rising temperature,with the 30℃group exhibiting a significantly higher feeding rate compared to the 15℃and 20℃groups.In terms of growth,the 25℃group achieved the highest weight gain and specific growth rate,significantly surpassing the 15℃group,while the 30℃group displayed the highest molting rate and was also significantly higher than the 15℃group.Enzyme activity analysis revealed that the 25℃group showed significantly higher activities of digestive enzymes(protease and amylase)than the other temperature groups.Additio-nally,this group demonstrated significantly elevated levels of antioxidant(total antioxidant capacity,superoxide dismu-tase,catalase)and nonspecific immune enzymes(acid phosphatase,alkaline phosphatase)compared to the other groups,indicating enhanced stress resistance and immune capacity at 25℃.Intestinal microbiota analysis indicated that the 20℃group had the highest microbial community richness(Observed OTUs,Chao1,Ace indices).However,at 25℃,significant alterations in community structure were observed at the phylum and genus levels:the relative abundances of Patescibacteria,Planctomycetota,and Bdellovibrionota decreased significantly.At the genus level,the beneficial Lysinibacillus increased significantly,while potential pathogens such as Candidatus Bacilloplasma,Shewanella,Pseu-domonas,and Pseudoxanthomonas decreased significantly.These findings suggest that 25℃is conducive to the growth of P.clarkii,enhancing its digestive enzyme activity,immune function,disease resistance,and significantly improving the intestinal microbiota structure.