Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa.
Department of Forestry, Fisheries and the Environment, Aquaculture Innovation and Technology Development, Roggebaai, South Africa.
J Phycol. 2023 Dec;59(6):1272-1283. doi: 10.1111/jpy.13391. Epub 2023 Oct 4.
Species of Ulva have a wide range of commercial applications and are increasingly being recognized as promising candidates for integrated aquaculture. In South Africa, Ulva has been commercially cultivated in integrated seaweed-abalone aquaculture farms since 2002, with more than 2000 tonnes of biomass cultivated per annum in land-based paddle raceways. However, the identity of the species of Ulva grown on these farms remains uncertain. We therefore characterized samples of Ulva cultivated in five integrated multi-trophic aquaculture farms (IMTA) across a wide geographical range and compared them with foliose Ulva specimens from neighboring seashores. The molecular markers employed for this study were the chloroplast-encoded Ribulose-1,5-bisphosphate carboxylase oxygenase (rbcL), the Internal Transcribed Spacer (ITS) of the nuclear, and the chloroplast elongation factor tufA. All currently cultivated specimens of Ulva were molecularly resolved as a single species, U. lacinulata. The same species has been cultivated for over a decade, although a few specimens of two other species were also present in early South African IMTA systems. The name Ulva uncialis is adopted for the Ulva "Species A" by Fort et al. (2021), Molecular Ecology Resources, 22, 86) significantly extending the distribution range for this species. A comparison with wild Ulva on seashores close to the farms resulted in five new distribution records for South Africa (U. lacinulata, U. ohnoi, U. australis, U. stenophylloides, and U. aragoënsis), the first report of a foliose form of U. compressa in the region, and one new distribution record for Namibia (U. australis). This study reiterates the need for DNA confirmation, especially when identifying morphologically simple macroalgae with potential commercial applications.
巨藻属的物种具有广泛的商业应用，越来越被认为是综合水产养殖有前途的候选物种。在南非，自 2002 年以来，巨藻一直在综合海藻-鲍鱼水产养殖农场中进行商业养殖，每年在陆基桨叶式养殖槽中培养超过 2000 吨的生物质。然而，这些农场种植的巨藻物种的身份仍然不确定。因此，我们对五个分布广泛的综合多营养水产养殖农场（IMTA）中培养的巨藻样本进行了特征描述，并将其与邻近海域的叶状巨藻标本进行了比较。本研究采用的分子标记是叶绿体编码的核酮糖-1,5-二磷酸羧化酶加氧酶（rbcL）、核内的内部转录间隔区（ITS）和叶绿体延伸因子 tufA。所有目前培养的巨藻样本均通过分子手段解析为单一物种，即 U. lacinulata。尽管在早期的南非 IMTA 系统中也存在其他两个物种的少数标本，但该物种已经被培育了十多年。福尔特等人（2021 年）采用 Ulva uncialis 这个名称来命名 Fort 等人（2021 年），《分子生态学资源》，22，86 年）显著扩展了该物种的分布范围。与靠近农场的近岸野生巨藻进行比较，导致南非出现了五个新的分布记录（U. lacinulata、U. ohnoi、U. australis、U. stenophylloides 和 U. aragoënsis），这是该地区首次报道叶状形式的 U. compressa，以及纳米比亚的一个新分布记录（U. australis）。本研究再次强调了 DNA 确认的必要性，特别是在识别具有潜在商业应用的形态简单的大型藻类时。
