Noctiluca scintillans is a bioluminescent dinoflagellate. They are one of the few organisms that can reproduce sexually by producing isogametes or asexually via binary fission. (Fukuda and Endoh 2006). Being able to reproduce both sexually and asexually is a huge advantage to an organism. There are both pros and cons to reproducing sexually as there are for reproducing asexually. Because Noctiluca scintillans are able to reproduce either way, they can maximize the amount of offspring they have. In times when the environment is stable, they can reproduce by binary fission and create offspring that are genetically identical. This is much more efficient than reproducing sexually and works well most of the time. However, if the environment is unstable, Noctiluca scintillans can reproduce sexually and introduce different alleles into the population that may be better adapted to a changing environment.

     A study looking at Noctiluca scintillans off the Gulf of Thailand showed that sexual reproduction only occurred during a southwest monsoon (Sriwoon et al. 2008). During the monsoon, Nociluca scintillans almost always switched from reproducing asexually to reproducing sexually. This study supported the theory that this organism will reproduce sexually only in an unstable environment.

     Noctiluca scintillans usually only reproduce asexually through binary fission, but will produce sexually in a changing environment. When producing sexually, Noctiluca scintillans produces isogametes (Fukuda and Endoh 2006). These are gametes that are similar in size and shape, but differ in allele frequencies. With isogametes there is no male or female gamete. Isogametes are haploid while the adult cell is diploid. During sexual reproduction, there are two haploid isogametes each with two flagella. These then form one diploid zygote with four flagella and as the zygote grows and becomes a trophont, the amount of flagella begins to decrease and the tentacle begins to form. In the final stage, the Noctiluca scintillans is a diploid organism with one flagella and one tentacle (Fukuda and Endoh 2006). 

    Cell reproduction generally occurs in the springtime when water temperatures are above 5-6° C (Sahling and Uhlig  1990).  Noctiluca scintillans can have huge blooms during reproduction and cause red tides. Noctiluca scintillans are often blamed for the death of fish during these blooms. They themselves are not toxic, but can have a build up of ammonia that is released during these red tides and may be the reason behind the increase in fish mortality during these blooms (Turkoglu 2013).

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