Gonyaulax utilize both asexual and sexual reproduction

Life cylce of a Dinoflagellate. © 1999  Allison Arnold and Monica Draghic                                                                       © 1999 Allison Arnold and Monica Draghic
     Asexual reproduction is the dominant form of reproduction. For Gonyaulax, binary fission or mitosis can take place. In
 mitosis the haploid parent cell (1n) undergoes asex and produces two identical daughter cells. These cells each acquire half of the theca (or cellulose plates) from
their parent, and exhibit the full set of plates as they mature.
    Because Gonyaulax contain a dinokaryotic nucleus and spend a majority of their life cycle in a haploid phase, binary fission commonly takes place. With this process, a haploid cell simply splits in half.

 Sexual reproduction is not very common with these organisms but it is utilized in the formation of cysts. The haploid adult cells are motile and form gametes via meiosis. In induction of the sexual phase, conjugation starts on the ventricle side of the cell once they pair. This forms an enlarged diploid planzygote. Depending on conditions, the planzygote with either form into a resting cyst or undergo meiosis to form a vegetative cell. Resting cysts—or hypozygotes, sink to the bottom of the ocean floor where they remain dormant until conditions are favorable. The cysts are shaped as an ellipse with rounded ends and covered by a wall of mucilaginous substance. Hypozygotes are provisioned with toxins and food reserves for they canspend a variable amount of time in this stage.

    To learn about the environmental relationships Gonyaulax catenella has with other organisms, follow the link to the interactions page!

     To appreciate the life cycle of another dinoflagellate, check out Alexandrium tamerense  or
Galerina autumnalis !