Urabe Misako, Sasai Takahide, Sokolov Sergey G
Faculty of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan.
Okinawa Churashima foundation Research Institute, 888 Ishikawa, Motobu, Okinawa, 905-0206, Japan.
Syst Parasitol. 2025 Jan 30;102(1):20. doi: 10.1007/s11230-025-10213-3.
Pulmovermis cyanovitellosus Coil and Kuntz, 1960 is a species of hemiurid trematode that localizes in the lung of sea snakes, an unusual trait for this group of parasites. Recent molecular phylogenetic studies based on 28S rRNA gene sequences have shown that this species is closely related to members of the genus Lecithochirium Lühe, 1901. This finding is unexpected given that Pulmovermis Coil and Kuntz, 1960 and Lecithochirium are currently classified in different subfamilies of Hemiuridae (Pulmoverminae Sandars, 1961 vs. Lecithochiriinae Lühe, 1901). To investigate this discrepancy, we conducted a comparative morphological study on new specimens of P. cyanovitellosus collected from the same locality as those in our previous research. These new specimens were compared with the paragenophores from our earlier study and with existing descriptions in literatures. This study provides the following new morphological data regarding P. cyanovitellosus: body surface covered with minute scales; massive muscular pads present on both sides of body at level of terminal genitalia; small esophageal pouch and Drüsenmagen present; seminal vesicle connecting to pars prostatica via aglandular duct; small, cylindrical sinus-sac present; ejaculatory vesicle absent; Juel's organ present; metraterm separated from uterus by conspicuous sphincter and connecting to distal end of pars prostatica. Additionally, we assessed the phylogenetic relationships of P. cyanovitellosus using the 28S rRNA gene, the internal transcribed spacer 2 (ITS2), and the cytochrome c oxidase subunit I (COI) gene markers. Phylogenetic analyses based on these markers demonstrated that P. cyanovitellosus clustered with species of Lecithochirium. Based on this molecular evidence, we conclude that Pulmovermis is a junior synonym of the genus Lecithochirium, and propose L. cyanovitellosum (Coil and Kuntz, 1960) Urabe and Sokolov comb. nov. Given the morphological similarities between Pulmovermis and Hydrophitrema Sandars, 1960, we also propose synonymizing the latter with Lecithochirium, and L. giganticum (Sandars, 1960) Urabe and Sokolov comb. nov. and L. pingtanense (Wang, 1980) Urabe and Sokolov comb. nov. are proposed. As a result, Pulmoverminae should be considered a junior synonym of Lecithochiriinae Lühe, 1901.
蓝卵肺吸虫（Pulmovermis cyanovitellosus）由科尔（Coil）和孔茨（Kuntz）于1960年发现，是半尾科吸虫的一种，寄生于海蛇肺部，这在该类寄生虫中较为罕见。近期基于28S rRNA基因序列的分子系统发育研究表明，该物种与1901年吕厄（Lühe）建立的枝睾属（Lecithochirium）的成员密切相关。鉴于1960年的肺吸虫属（Pulmovermis）和枝睾属目前被分类在半尾科的不同亚科中（1961年的肺吸虫亚科（Pulmoverminae）与1901年的枝睾亚科（Lecithochiriinae）），这一发现出乎意料。为研究这种差异，我们对从与之前研究相同地点采集的蓝卵肺吸虫新标本进行了比较形态学研究。这些新标本与我们早期研究中的副模式标本以及文献中的现有描述进行了比较。本研究提供了关于蓝卵肺吸虫的以下新形态学数据：体表覆盖微小鳞片；在生殖孔末端水平的身体两侧有大量肌肉垫；有小食管囊和腺胃；精囊通过无腺管连接到前列腺部；有小的圆柱形窦囊；无射精囊；有尤尔氏器官；子宫末段通过明显的括约肌与子宫分开，并连接到前列腺部远端。此外，我们使用28S rRNA基因、内部转录间隔区2（ITS2）和细胞色素c氧化酶亚基I（COI）基因标记评估了蓝卵肺吸虫的系统发育关系。基于这些标记的系统发育分析表明，蓝卵肺吸虫与枝睾属的物种聚类。基于这一分子证据，我们得出结论，肺吸虫属是枝睾属的次异名，并提议将蓝卵枝睾吸虫（Lecithochirium cyanovitellosum）（科尔和孔茨，1960年）作为新组合（Urabe和Sokolov，新组合）。鉴于肺吸虫属与1960年桑德尔斯（Sandars）建立的水蛇吸虫属（Hydrophitrema）形态相似，我们还提议将后者与枝睾属同义，并提出巨型枝睾吸虫（Lecithochirium giganticum）（桑德尔斯，1960年）（Urabe和Sokolov，新组合）和平潭枝睾吸虫（Lecithochirium pingtanense）（王，1980年）（Urabe和Sokolov，新组合）。因此，肺吸虫亚科应被视为1901年枝睾亚科的次异名。
