Faculty of Agriculture, Kindai University, Nara, Japan.
Graduate School of Agriculture, Kindai University, Nara, Japan.
PLoS One. 2022 Oct 6;17(10):e0275211. doi: 10.1371/journal.pone.0275211. eCollection 2022.
We investigated the succession process of intestinal bacteria during seed production in full-cycle aquaculture of Pacific bluefin tuna (Thunnus orientalis). During the seed production, eggs, healthy fish, rearing water, and feeds from three experimental rounds in 2012 and 2013 were collected before transferring to offshore net cages and subjected to a fragment analysis of the bacterial community structure. We identified a clear succession of intestinal bacteria in bluefin tuna during seed production. While community structures of intestinal bacteria in the early stage of larvae were relatively similar to those of rearing water and feed, the bacterial community structures seen 17 days after hatching were different. Moreover, although intestinal bacteria in the late stage of larvae were less diverse than those in the early stage of larvae, the specific bacteria were predominant, suggesting that the developed intestinal environment of the host puts selection pressure on the bacteria in the late stage. The specific bacteria in the late stage of larvae, which likely composed 'core microbiota', were also found on the egg surface. The present study highlights that proper management of the seed production process, including the preparation of rearing water, feeds, and fish eggs, is important for the aquaculture of healthy fish.
我们研究了全周期养殖模式下，太平洋蓝鳍金枪鱼（Thunnus orientalis）在亲鱼培育过程中肠道细菌的演替过程。在亲鱼培育期间，我们于 2012 年和 2013 年的三个实验阶段，在将亲鱼转移到近海网箱之前，收集了卵、健康鱼、养殖用水和饲料，并对细菌群落结构进行了片段分析。我们发现，在亲鱼培育过程中，蓝鳍金枪鱼的肠道细菌有明显的演替现象。虽然早期幼虫的肠道细菌群落结构与养殖用水和饲料的结构相对相似，但孵化后 17 天的肠道细菌结构则不同。此外，尽管晚期幼虫的肠道细菌多样性不如早期幼虫丰富，但特定细菌占据主导地位，这表明宿主发育良好的肠道环境对后期细菌产生了选择压力。晚期幼虫的特定细菌，可能构成了“核心微生物组”，也存在于卵表面。本研究强调，适当管理亲鱼培育过程，包括养殖用水、饲料和鱼卵的准备，对于健康鱼类的养殖非常重要。
