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SEXUAL REPRODUCTION IN THE TOXIC DINOFLAGELLATE GONYAULAX MONILATA 1
Author(s) -
Walker Linda M.,
Steidinger Karen A.
Publication year - 1979
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.0022-3646.1979.00312.x
Subject(s) - biology , dinoflagellate , zygote , cytoplasm , botany , benthic zone , sexual reproduction , nucleus , biophysics , microbiology and biotechnology , ecology , embryogenesis , embryo
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 zygates 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.