College of Fishery and Life Science, Shanghai Ocean University, Shanghai 201306, China; Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
Eur J Protistol. 2013 Nov;49(4):634-43. doi: 10.1016/j.ejop.2013.04.005. Epub 2013 May 18.
We investigate the living morphology, infraciliature, and small subunit rRNA gene sequences of two poorly known marine euplotids, Aspidisca fuscaKahl, 1928 and A. hexerisQuennerstedt, 1869, isolated from intertidal sewage outfall, northern China and sandy sediments, southern China, respectively. Improved diagnoses and morphometric data are provided for both species. Aspidisca fusca is characterized by having a peristomial spur, seven frontoventral cirri in a "polystyla-arrangement", and two oval macronuclear nodules. Aspidisca hexeris can be recognized by having an elliptical body shape, a peristomial spur, seven membranelles in the anterior portion of adoral zone and 11-13 in the posterior part, as well as seven frontoventral cirri arranged in two oblique rows. In addition, the presence and degree of projections along the left margin of A. hexeris are highly variable among populations. Phylogenetic analyses based on small subunit rRNA gene sequence data support the validity of both A. hexeris and A. fusca as distinct species, and indicate that A. fusca is most closely related to A. aculeata and A. steini, whereas A. hexeris shows a close relationship with A. magna.
我们研究了分别从中国北方的潮间带污水排放口和中国南方的沙质沉积物中分离到的两种海洋游仆虫属（Euplotidium）的 Aspidisca fusca Kahl, 1928 和 A. hexeris Quennerstedt, 1869 的活体形态、纤毛结构和小亚基 rRNA 基因序列。为这两个物种提供了改进的诊断和形态计量学数据。Aspidisca fusca 的特征是具有口围刺，前腹纤毛七根呈“多枝型排列”，还有两个椭圆形的大核结节。Aspidisca hexeris 可以通过其椭圆形的体型、口围刺、口前庭区有 7 根膜质纤维和后区有 11-13 根膜质纤维以及 7 根前腹纤毛排列成两斜行来识别。此外，A. hexeris 左侧边缘的突起的存在和程度在不同种群中变化很大。基于小亚基 rRNA 基因序列数据的系统发育分析支持 A. hexeris 和 A. fusca 作为两个不同物种的有效性，并表明 A. fusca 与 A. aculeata 和 A. steini 关系最密切，而 A. hexeris 与 A. magna 关系密切。
