Morphology, ultrastructure, and phylogeny of Protodinium simplex and Biecheleriopsis cf. adriatica (Dinophyceae) from the China Sea
Luo, Zhaohe; Yang, Weidong; Xu, Bin; Zheng, Bingxin; Gu, Haifeng
The presence of the genera Protodinium and Biecheleriopsis in the China Sea has not been reported previously. In the present study, three strains of Protodinium simplex and eleven strains of Biecheleriopsis cf. adriatica were established from the China Sea and subjected to detailed examinations using light microscopy, scanning electron microscopy, and transmission electron microscopy. Protodinium simplex possessed an elongated apical vesicle (EAV) on the apex, and the epicone, cingulum, and hypocone each contained three latitudinal series of vesicles. Thin sections revealed that P. simplex possessed a type E eyespot, thus supporting its classification within the family Suessiaceae. Biecheleriopsis cf. adriatica was morphologically identical to B. adriatica, as it possessed an EAV and 4, 3, and 3 latitudinal series of vesicles on the epicone, cingulum, and hypocone, respectively, but it lacked swollen ends of thylakoids in the pyrenoids and rhizoplast. Morphologically, Protodinium and Biecheleriopsis were nearly indistinguishable, separated only by the number of EAV knobs. Phylogenetic analyses based on large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer region (ITS) sequences confirmed their close relationship.