JOURNAL OF PLANKTON RESEARCH | VOLUME 9 | NUMBER 2 | PAGES 291-295 | 1987
© Oxford University Press
research-article |
Notes on the life history of the planktonic alga, Dysmorphococcus globosus (Volvocales)
1Thomas Hunt Morgan School of Biological Sciences, University of Kentucky Lexington, KY 40506, USA Department of Biology, Pittsburg State University Pittsburg, KS 66762
Received on August 1, 1986; accepted on November 1, 1986 Several strains of Dysmorphococcus globosus, a planktonic green flagellate, were examined during this study. Dysmorphococcus globosus has a generation rime of 48 h, at which time four bi-flagellated daughter cells were released. In some instances, four to eight, rarely 16, noo-flagellated aplanospores will be formed per cell, germinating when placed in fresh medium with the subsequent release of from one to four motile individuals. Sexual reproduction was recorded in detail for the first time although it had been previously reported that pairs of individual cells had been observed attached at their anterior poles. Sexual reproduction was isogamous to anisogamous with the clones being homothallic. During zygote germination, the zygote undergoes two rapid divisions to form four products of meiosis which were released following rupture of the lorica.