Abstract Recirculating aquaculture systems (RAS) can be installed indoors, allowing year-round production of tropical animals in nearly any climate. A nursery phase is commonly used in Litopenaeus vannamei production since it allows for enhanced biosecurity and better quantification of animals while reducing space requirements. However, it is unclear whether animal density and inclusion of artificial substrate may improve shrimp performance during the nursery phase. In this experiment, we compared shrimp production parameters in two stocking densities with or without the use of an artificial substrate by creating four treatments: low-density LD; 1500 PL/m−3, low-density with substrate LDS, high-density HD; 3000 PL/m−3), and high-density with substrate (HDS). The LDS and HDS treatments included 0.46-m2 of high-density polyethylene 2.5-cm mesh as a substrate, which increased the tank surface area by 21 %. Each treatment was randomly assigned to four 160-l culture tanks, each with a biofilter. The shrimp had an initial weight of 4 mg and were grown for 50 days. The low-density treatments had significantly higher dissolved oxygen (DO) and pH than the high-density treatments (P ≤ 0.001). Specifically, LDS had the highest DO and pH followed by the LD, HD, and HDS treatments, respectively. High-density treatments had significantly higher NO2-N levels than low-density treatments during week 2 of the experiment when an unusually high concentration of nitrite was observed. FCR was significantly lower in both low-density treatments than in high-density treatments. At harvest, the total biomass (kg m−3) was significantly higher in high-density treatments than in low-density treatments (P ≤ 0.001), and the HDS treatment had a significantly greater biomass output than HD. Producers should consider artificial substrate and higher densities during nursery production to maximize shrimp production; however, the effects on water quality should also be taken into account.

中文翻译：

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密度和人工基质对集约化南美白对虾育苗生产的影响

摘要 循环水产养殖系统 (RAS) 可以安装在室内，几乎可以在任何气候下全年生产热带动物。南美白对虾生产中通常使用育苗阶段，因为它可以增强生物安全性和更好地量化动物，同时减少空间需求。然而，尚不清楚动物密度和人工基质的加入是否可以提高虾苗阶段的生产性能。在本实验中，我们通过创建四种处理方式比较了两种放养密度下使用或不使用人工基质的虾生产参数：低密度 LD；1500 PL/m−3，低密度，带基板 LDS，高密度 HD；3000 PL/m-3) 和高密度基板 (HDS)。LDS 和 HDS 处理包括 0.46 平方米的高密度聚乙烯 2。5 厘米网作为基材，将水箱表面积增加了 21%。每个处理被随机分配到四个 160 升的培养池中，每个池都有一个生物过滤器。虾的初始重量为 4 毫克，并生长了 50 天。低密度处理的溶解氧 (DO) 和 pH 值显着高于高密度处理 (P ≤ 0.001)。具体而言，LDS 具有最高的 DO 和 pH 值，其次是 LD、HD 和 HDS 处理。在实验的第 2 周，当观察到异常高浓度的亚硝酸盐时，高密度处理的 NO2-N 水平明显高于低密度处理。两种低密度处理的 FCR 均显着低于高密度处理。收获时，高密度处理的总生物量（kg m−3）显着高于低密度处理（P ≤ 0.001），并且 HDS 处理的生物量输出显着高于 HD。生产者在育苗生产中应考虑人工基质和更高的密度，以最大限度地提高虾产量；然而，还应考虑对水质的影响。