养殖业板块9月1日跌0.42%，正邦科技领跌，主力资金净流出4.58亿元

Group 1 - The aquaculture sector experienced a decline of 0.42% on September 1, with Zhengbang Technology leading the losses [1] - The Shanghai Composite Index closed at 3875.53, up 0.46%, while the Shenzhen Component Index closed at 12828.95, up 1.05% [1] - Key stocks in the aquaculture sector showed varied performance, with Xiaoming Co. rising by 1.27% and Zhengbang Technology falling by 1.96% [2] Group 2 - The net outflow of main funds in the aquaculture sector was 458 million yuan, while retail investors saw a net inflow of 189 million yuan [2] - Major stocks like Juxing Agriculture experienced a net inflow of 15.16 million yuan from main funds, while Shennong Group had a net inflow of 4.79% from retail investors [3] - The trading volume for Zhengbang Technology was 1.3968 million shares, with a total transaction value of 422 million yuan [2]