Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 10072, Vietnam.
Coastal Branch of Joint Vietnam-Russia Tropical Science and Technology Research Centre, 30 Nguyen Thien Thuat, Nha Trang, Khanh Hoa 57000, Vietnam.
J Parasitol. 2024 Jul 1;110(4):393-401. doi: 10.1645/24-2.
Myxospores discovered floating free in the bile of marine fishes from the south-central coast of Vietnam were identified using morphological and molecular methods, leading to the description of 2 new species. Ceratomyxa chauvanminhi n. sp. was detected in 16% (8/50) of cultured barramundi Lates calcarifer (Bloch) specimens, and Ceratomyxa sekoi n. sp. was found in 20% (5/25) of wild largehead hairtail Trichiurus lepturus Linnaeus specimens. The spores of C. chauvanminhi n. sp. are very shallowly ovoid, slightly crescent shaped, and 11.5 ± 0.5 (10.7-12.4) μm thick, 5.8 ± 0.2 (5.4-6.1) μm long, and 5.5 ± 0.2 (5.2-5.7) μm wide. Their posterior angles are slightly concave at 158.7° ± 4.2° (151.3°-164.8°), and they possess 2 equal spherical polar capsules 2.5 ± 0.2 (2.1-2.9) μm in diameter. The spores of C. sekoi n. sp. are 5.6 ± 0.2 (5.0-6.1) μm long, 75.5 ± 4.8 (68.9-90.0) μm thick, and 5.5 ± 0.1 (5.4-5.6) μm wide, with 2 equal, slightly anterior spherical polar capsules 2.1 ± 0.2 (1.7-2.4) μm in diameter. Although C. sekoi n. sp. spores resemble those of species of MyxodavisiaZhao, Zhou, Kent, and Whipps, 2008, characterized by long tapering valves, genetic analyses distinctly place this new species within the Ceratomyxa Thélohan, 1892 lineage. This study contributes to the understanding myxosporean diversity in Vietnamese waters and highlights the difficulty associated with distinguishing between the genera Ceratomyxa and Myxodavisia.
从越南中南部沿海的海洋鱼类胆汁中发现的自由漂浮的粘孢子虫，通过形态学和分子方法进行了鉴定，从而描述了 2 个新种。Ceratomyxa chauvanminhi n. sp. 在 16%（8/50）的养殖尖鳍鲈（Lates calcarifer）标本中被检测到，而 Ceratomyxa sekoi n. sp. 在 20%（5/25）的野生大眼鲷（Trichiurus lepturus）标本中被发现。C. chauvanminhi n. sp. 的孢子非常浅的卵形，略带新月形，厚 11.5±0.5（10.7-12.4）μm，长 5.8±0.2（5.4-6.1）μm，宽 5.5±0.2（5.2-5.7）μm。它们的后角在 158.7°±4.2°（151.3°-164.8°）处略微凹陷，并且它们具有 2 个相等的球形极囊，直径为 2.5±0.2（2.1-2.9）μm。C. sekoi n. sp. 的孢子长 5.6±0.2（5.0-6.1）μm，厚 75.5±4.8（68.9-90.0）μm，宽 5.5±0.1（5.4-5.6）μm，具有 2 个相等的、略微靠前的球形极囊，直径为 2.1±0.2（1.7-2.4）μm。尽管 C. sekoi n. sp. 的孢子类似于由 Zhao、Zhou、Kent 和 Whipps 于 2008 年描述的 Myxodavisia 属的孢子，具有长而渐细的瓣片，但遗传分析明确将这个新种置于 Ceratomyxa Thélohan，1892 谱系内。本研究有助于了解越南水域粘孢子虫的多样性，并强调了区分 Ceratomyxa 和 Myxodavisia 属的困难。
