The research of ultrastructure for different morphological cells of Haematococcus pluvialis

By transmission electron microscopy, the ultrastructure investigated of motile cells and non-motile cells in Haematococcus pluvialis were compared. The results show that the major morphological characters of the motile cells are similar to those of volvocales. But the thinner wall is separated from the protoplast by periplasmic space, and the chloroplasts are reticulate which can proliferate during cell reproduction. In non-motile cells, the major distinctive characters are following: a. The structures of chloroplasts gradually change into compact, and some large mitochondrias present in the young non-motile cells. b. The cytoplasm of mature non-motile cells are practically full of astaxanthin deposits, and the new walls of protoplasts are very thick. The physiological differences are discussed the physiological difference between motile cells and non-motile cells in terms of their morphological and ultrastructural changes.