加州鲈 + 河蟹箱塘联动养殖模式与河蟹单养模式下底泥微生物多样性研究

Comparative Study on Sediment Microbial Diversity between Integrated Largemouth Bass and Chinese Mitten Crab Culture and Monoculture of Chinese Mitten Crab

摘要: 本研究通过16S rRNA基因高通量测序技术，比较了箱塘联动生态养殖模式(加州鲈套养)与传统河蟹单养模式下池塘底泥细菌群落结构特征及季节动态差异。结果表明，变形菌门为两种养殖模式的核心优势菌门，但套养塘中拟杆菌门丰度显著升高，硝化螺旋菌门相对减少。在纲水平上，γ-变形菌纲为绝对优势类群，套养塘拟杆菌纲占比提升而芽单孢菌纲下降。Alpha多样性分析显示，单养塘微生物丰富度(Chao1指数)在多数月份高于套养塘，且两者均呈现“先升后降”的养殖周期性变化规律。套养模式虽能提升经济效益，但底泥有机质积累导致拟杆菌门等兼性厌氧菌增殖，可能削弱氮循环功能菌(硝化螺旋菌门)作用，增加水体富营养化风险。研究提示，需通过人工调控优化套养模式微生物结构，平衡生态效益与经济效益，为绿色水产养殖提供科学依据。

Abstract: This study employed high-throughput 16S rRNA gene sequencing to compare the composition and seasonal dynamics of bacterial communities in pond sediments under two aquaculture models: an integrated “cage-in-pond” system co-culturing largemouth bass (Micropterus salmoides) with Chinese mitten crab (Eriocheir sinensis), and a traditional monoculture of E. sinensis. Proteobacteria was the dominant phylum in both systems, while Bacteroidetes showed significantly higher abundance and Nitrospirae lower abundance in the integrated system. At the class level, Gammaproteobacteria remained dominant, with increased Bacteroidia and decreased Gemmatimonadetes in co-cultured ponds. Alpha diversity analysis showed that microbial richness (Chao1 index) was generally higher in the monoculture system during most months, and both systems exhibited a “rise-then-fall” trend throughout the culture cycle. Although the integrated model improves economic returns, organic matter accumulation in sediments may promote the growth of facultative anaerobes like Bacteroidetes, reduce nitrogen-cycling bacteria (Nitrospirae), and elevate the risk of eutrophication. These findings suggest that artificial regulation of microbial communities is needed to balance ecological health with economic benefits and to support sustainable aquaculture practices.