Division of Earth Environmental System Science, Pukyong National University, Busan 48513, Republic of Korea.
Division of Earth Environmental System Science, Pukyong National University, Busan 48513, Republic of Korea; Department of Oceanography, Pukyong National University, Busan 48513, Republic of Korea.
Eur J Protistol. 2021 Jun;79:125797. doi: 10.1016/j.ejop.2021.125797. Epub 2021 Apr 23.
During daily monitoring in Yongho Bay off Busan, Korea in 2019, an isolate of the dinoflagellate genus Heterocapsa was established in clonal culture. Light and electron microscopic examination revealed that the isolate was ellipsoid in shape, exhibiting a thecal plate arrangement (Po, cp, X, 5', 3a, 7″, 6c, 5s, 5‴, 2'''') consistent with most other Heterocapsa species. A large, elongated nucleus was positioned on the left side of the cell, a single reticulate chloroplast was located peripherally, and a single, starch-sheathed, spherical pyrenoid was present in the episome or near the cingulum. Morphologically, the isolate most closely resembles H. circularisquama and H. illdefina. Transmission electron microscopic examination of whole mounts revealed that the isolate had two body scale types, one of which was a complex, three-dimensional, fine structure distinct from other Heterocapsa species, whereas the other simpler type was structurally similar to the scales of H. horiguchii. Molecular phylogeny based on rRNA sequences revealed that the isolate was distantly related to morphologically similar species, but formed a sister lineage to H. horiguchii, a species characterized by a similar body scale morphology. Based on morphological, ultrastructural, and molecular data, we proposed it as a new species, Heterocapsa busanensis sp. nov.
在 2019 年韩国釜山永宗湾的日常监测中，建立了一株菱形藻属（Heterocapsa）的克隆培养物。光镜和电镜检查表明，该分离株呈椭圆形，具壳板排列（Po，cp，X，5'，3a，7″，6c，5s，5‴，2'''），与大多数其他菱形藻属物种一致。一个大的、拉长的细胞核位于细胞的左侧，一个单一的网状叶绿体位于周边，一个单一的、淀粉鞘的、球形的淀粉核位于周质体或靠近环带。形态上，该分离株与 H. circularisquama 和 H. illdefina 最为相似。整个装片的透射电子显微镜检查显示，该分离株有两种体型鳞片，一种是复杂的、三维的、不同于其他菱形藻属物种的精细结构，而另一种较简单的类型在结构上与 H. horiguchii 的鳞片相似。基于 rRNA 序列的分子系统发育分析表明，该分离株与形态相似的物种亲缘关系较远，但与 H. horiguchii 形成姐妹谱系，后者的特征是具有相似的体型鳞片形态。基于形态学、超微结构和分子数据，我们提出它是一个新种，命名为釜山菱形藻（Heterocapsa busanensis sp. nov.）。
