SEXUAL REPRODUCTION IN THE TOXIC DINOFLAGELLATEGONYAULAX MONILATA1

Authors:
Publisher website
Google Scholar
Abstract
The sexual cycle ofGonyaulax monilataHowell 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.

This publication has 10 references indexed in Scilit: