双眦榴弹虫和济州琵琶列维榴弹虫的形态学和分子系统学研究
Morphology and molecular phylogeny of two colepid species from China, Coleps amphacanthus Ehrenberg, 1833 and Levicoleps biwae jejuensis Chen et al., 2016 (Ciliophora, Prostomatida)
-
摘要: 本文首次报道了两种榴弹虫科纤毛虫的中国种群:双眦榴弹虫(Coleps amphacanthus Ehrenberg, 1833)与济州琵琶列维榴弹虫(Levicoleps biwae jejuensis. Chen et al., 2016)。通过现代研究方法揭示其形态特征、纤毛图式及分子系统地位。基于本研究结果,给出双眦榴弹虫的新定义:虫体体形为“桶”状,大小约100×50微米;体动基列22-28,每列由14-21个单动基系及2个围口双动基系组成;尾纤毛5-10根;伸缩泡1个。此外,结合历史文献与本研究,修订了济州琵琶列维榴弹虫的定义。基于SSU rRNA信息,探讨两种的分子系统学地位,结果表明:双眦榴弹虫与列维榴弹虫属种类系统地位更为接近,聚为一枝,而其余榴弹虫属内所有种类聚为一枝。Abstract: Two colepid ciliates, Coleps amphacanthus Ehrenberg, 1833 and Levicoleps biwae jejuensis Chen et al., 2016, were first recorded in China. Their living morphology, infraciliature and small subunit (SSU) rRNA gene sequences were determined using standard methods. The improved diagnosis of Coleps amphacanthus is as follows:cell size about 100×50 μm in vivo, barrel-shaped; 22-28 ciliary rows each composed of about 14-21 monokinetids and two perioral dikinetids; 5-10 caudal cilia; and one terminal contractile vacuole. Levicoleps biwae jejuensis was also investigated, with an improved diagnosis given based on previous and present work. The phylogenetic analyses based on SSU rRNA gene sequences revealed that all Coleps species were grouped together, except for Coleps amphacanthus, which was grouped into a clade of the genus Levicoleps.