Sexual Reproduction in the Toxic Dinoflagellate Gonyaulax Monilata
Walker LM and Steidinger KA. 1979. Sexual Reproduction in the Toxic Dinoflagellate Gonyaulax Monilata. Journal of Phycology. 15:312-315
The sexual cycle of Gonyaulax monilata Howell was observed in stationary cultures and in nitrogen-deficient medium. The armored, isogamous gametes fuse in a characteristic manner with cingula at oblique angles. Nuclear fusion lags slightly behind cytoplasmic fusion. The zygote enlarges for several days. The dark, double-flagellated planozygote encysts within 1-3 wk. Early hypnozygotes are round to ovoid and contain lipid and one or two large golden-yellow globules. As the hypnozygote matures, the globules become smaller and the cytoplasm darkens and pulls from the wall. All cysts examined contained only one nucleus. A very dark, uninucleate post-hypnozygotic cell escapes through an archeopyle and within 24 h divides into daughter cells which divide in 24-48 h forming a small chain. The production of thick walled zygotes in culture implies that such resting stages in marine sediments could serve as a source stock for blooms. This species causes toxic red tides and the existence of benthic "seed beds" consisting of hypnozygotes is now plausible.
- Type
- Journal Article
- Authors
- Walker, Linda; Steidinger, Karen
- Units
- SFCN
- Keywords
- Globules, Hypnozygotes, Isogamous Gametes, Nuclear Fusion, Sexual Cycle