Original paper

The microstructure and ultrastructure of Arthrospira platensis (Hormogonophyceae, Cyanophyta) in alkaline lakes of Erdos Plateau, China

Xiu-Ying, Tian; Chen, Qiao; Ling-Yan, Gao


In 1996 we first detected Arthrospira platensis (Nordst.) Gom. in Lake Bayannur, an alkaline lake, and others nearby lakes in Mo Us Sandy Land of Erdos Plateau in P. R. China. Since isolation from previously described populations might induce genetic drift, the objectives of our study were to describe the morphology and anatomical structures of the species in Lake Bayannur and to compare them with those reported in the literature. We used both a light microscope (LM) and an electron microscope (EM) to observe the microstructure and the ultrastructure of A. platensis. Our results indicate: A. platensis was a dark blue-green, multicellular filaments organism without branches. It had a trichome spiral coil with mostly 7 to 10 spirals; each spiral was 32 to 45 μm wide; and the distance between two spirals 27 μm to 60 μm. The cells varied in width from 7.3 μm to 9.0 μm and in length from 4.5 μm to 6.3 μm and were slightly constricted at the cross-walls. The ends of the trichomes were mostly obtuse-spherical, with a few being calyptrate or inflated. The protoplast was divided into two parts : the central area (central body) and surrounding area of the cell. The central body consisted of nuclear materials, typical of a prokaryotic cell. The trichome surface was covered by anastomosed ribs and flat verruciform protuberances with different diameters. The latter structures have not been reported previously and distinguish this species from that found in Lake Chad in Africa.


cytological structuresmorphologyarthrospira platensislake bayannurchina