Azaspiracids (AZA) are the most recently discovered group of lipophilic marine biotoxins of microalgal origin, and associated with human incidents of shellfish poisoning. They are produced by a few species of Amphidomataceae, but diversity and occurrence of the small-sized dinophytes remain poorly explored for many regions of the world. In order to analyze the presence and importance of Amphidomataceae in a highly productive area of Argentinean coastal waters (El Rincón area, SW Atlantic), a scientific cruise was performed in 2015 to sample the early spring bloom. In a multi-method approach, light microscopy was combined with real-time PCR molecular detection of Amphidomataceae, with chemical analysis of AZA, and with the establishment and characterization of amphidomatacean strains. Both light microscopy and PCR revealed that Amphidomataceae were widely present in spring plankton communities along the El Rincón area. They were particularly abundant offshore at the shelf front, reaching peak densities of 2.8 × 10⁵ cells L⁻¹, but no AZA were detected in field samples. In total, 31 new strains were determined as Az. dalianense and Az. spinosum, respectively. All Az. dalianense were non-toxigenic and shared the same rRNA sequences. The large majority of the new Az. spinosum strains revealed for the first time the presence of a non-toxigenic ribotype of this species, which is otherwise the most important AZA producer in European waters. One of the new Az. spinosum strains, with a particular slender shape and some other morphological peculiarities, clustered with toxigenic strains of Az. spinosum from Norway and, exceptionally for the species, produced only AZA-2 but not AZA-1. Results indicate a wide diversity within Az. spinosum, both in terms of sequence data and toxin profiles, which also will affect the qualitative and quantitative performance of the specific qPCR assay for this species. Overall, the new data provide a more differentiated perspective of diversity, toxin productivity and occurrence of Amphidomataceae in a poorly explored region of the global ocean.

氮杂螺菌酸（AZA）是最近发现的微藻来源的亲脂性海洋生物毒素，与人类贝类中毒事件有关。它们是由少数两栖类科植物产生的，但在世界许多地区，对小型双生植物的多样性和发生情况仍然缺乏探索。为了分析两栖动物科在阿根廷沿海水域高产地区（西南大西洋，ElRincón地区）的存在和重要性，2015年进行了一次科学巡游，对早春开花进行了采样。采用多方法方法，将光学显微镜与两栖动物科的实时PCR分子检测，AZA的化学分析以及两栖动物科菌株的建立和鉴定相结合。光学显微镜和PCR均显示，沿ElRincón地区的春季浮游生物群落中广泛存在两性纲。它们在货架前部海上特别丰富，最高密度达到2.8×10^5个细胞L ^-1，但在野外样品中未检测到AZA。总共确定了31个新菌株为Az。大连和阿兹。分别为刺肌。所有Az。dalianense无毒，并具有相同的rRNA序列。新Az的绝大部分。spinosum菌株首次揭示了该物种的非毒性核糖型，否则它是欧洲水域中最重要的AZA生产者。新的Az之一。具特定细长形状和某些其他形态特征的刺糖菌株与产毒素的Az菌株聚集在一起。刺糖来自挪威，而且对于该物种而言，例外的是仅生产AZA-2，而不生产AZA-1。结果表明在Az内有很大的多样性。无论是在序列数据还是在毒素谱方面，都认为刺孢菌会影响该物种特异性qPCR分析的定性和定量性能。总体而言，新数据为全球海洋勘探程度较差的地区提供了更加多样化的多样性，毒素生产力和两性科的观点。