Library of Marine Samples, Korea Institute of Ocean Science & Technology, Geoje, 656-830, Republic of Korea.
Faculty of Marine Technology, Chonnam National University, Yeosu, 59626, Republic of Korea.
Harmful Algae. 2019 Nov;89:101686. doi: 10.1016/j.hal.2019.101686. Epub 2019 Oct 7.
In Japanese, Chinese and Korean coastal waters, recurrent blooms of a small, elongate Prorocentrum species have been observed in recent years. In previous studies, this species has been respectively identified as P. shikokuense, P. donghaiense and P. dentatum, despite morphological similarity and identical rDNA sequences. To resolve the confusion, morphological features, including the architectural details of the periflagellar area, were examined and ribosomal DNA (rDNA) sequences were obtained from specimens collected from the East China Sea and Korean coast, and a strain established in the waters off the Canary Islands of Spain. In addition, the descriptions of the three species and allied species were reviewed. Morphological observations and a phylogeny based on the SSU, ITS region and LSU rDNA sequences revealed that the previously confused species and our studied strains are conspecific and that the morphology of strains identified as P. dentatum in the phylogenetic trees does not coincide with P. dentatum sensu stricto. The confusion can be traced back to Dodge (1975, p. 116), who considered P. veloi, P. monacense and P. obtusidens as junior heterotypic synonyms of P. dentatum. However, Dodge's P. dentatum are closer to P. obtusidens sensu stricto, rather than P. dentatum sensu stricto. P. obtusidens sensu stricto can be distinguished from P. dentatum sensu stricto by its relatively small size, parallel sides towards the anterior and a blunt anterior extension on one side. This indicates that P. obtusidens should not be considered a synonym of P. dentatum sensu stricto. In addition, a comparison of the original descriptions of P. obtusidens and allied species allowed to conclude that small, elongate Prorocentrum from Japanese, Chinese and Korean coastal waters previously identified as P. shikokuense, P. donghaiense, P. dentatum sensu Yoo and Lee (1986) and the specimens studied herein, which share identical rDNA sequences, morphologically coincide with P. obtusidens. Therefore, it is proposed that P. shikokuense and P. donghaiense should be regarded as junior synonyms of P. obtusidens.
近年来，在日本、中国和朝鲜沿海海域，人们观察到一种小型细长的原甲藻属物种频繁出现水华。在之前的研究中，该物种分别被鉴定为 P. shikokuense、P. donghaiense 和 P. dentatum，尽管形态相似且 rDNA 序列相同。为了解决这一混淆，我们检查了形态特征，包括鞭毛周围区的建筑细节，并从东海和朝鲜海岸采集的标本以及在西班牙加那利群岛水域建立的一个品系中获得了核糖体 DNA（rDNA）序列。此外，还回顾了这三个物种和相关物种的描述。形态观察和基于 SSU、ITS 区和 LSU rDNA 序列的系统发育分析表明，之前混淆的物种和我们研究的菌株是同一种，并且在系统发育树中被鉴定为 P. dentatum 的菌株的形态与 P. dentatum 不符。这种混淆可以追溯到 Dodge（1975 年，第 116 页），他认为 P. veloi、P. monacense 和 P. obtusidens 是 P. dentatum 的次异名。然而，Dodge 的 P. dentatum 更接近 P. obtusidens 而不是 P. dentatum。P. obtusidens 可以通过其相对较小的尺寸、朝向前部的平行侧面和一侧的钝形前部延伸与 P. dentatum 区分开来。这表明 P. obtusidens 不应被视为 P. dentatum 的同义词。此外，对 P. obtusidens 和相关物种的原始描述进行比较后，可以得出结论，以前在日本、中国和朝鲜沿海海域被鉴定为 P. shikokuense、P. donghaiense、Yoo 和 Lee（1986 年）的 P. dentatum 和本文研究的标本，这些标本具有相同的 rDNA 序列，在形态上与 P. obtusidens 一致。因此，建议将 P. shikokuense 和 P. donghaiense 视为 P. obtusidens 的次同义词。
