<p>Enhancing our understanding of the role of microbial life strategies and their trade-offs in the functioning of microbial communities is essential for improving the management of microbial communities. In aquaculture microbiomes, management aimed at increasing the dominance of K-strategists has experimentally been shown to influence cultivation performance. To understand the mechanisms behind such observations, we need to improve our understanding of the typical properties and behaviour of r- and K-strategists. Several studies have advanced our understanding of theoretical trade-offs that may shape these life strategies, but our understanding of which trade-offs are relevant under natural conditions is still limited. In this study, we investigated the in situ growth strategies of bacterial taxa in rearing water microbiomes of whiteleg shrimp (<i>Litopenaeus vannamei</i>) larviculture by reconstructing 67 high quality metagenome assembled genomes (MAGs), which covered between 31 and 85% of the sampled communities. We found evidence for niche separation between r- and K-biased strategists residing in these communities, with r-biased strategists typically encoding more and more versatile transport and metabolism pathways, and having a higher fitness for exploitation of spatially structured nutrient hotspots. We further increased the knowledge regarding the influence of r- and K-biased strategistson aquaculture cultivation performance by showing that the in situ growth activity of r-biased strategists could be linked better with cultivation performance than the relative abundance of r- and K-biased strategists.</p>