Pyrocystis fusiformis

''Pyrocystis fusiformis's name is derived from its tapered or spindle shape. P. fusiformis'' is non-motile, which is a characteristic of all members of family Pyrocystaceae, which lose their flagellum by the time these organisms are adults. with each cell being approximately 970 x 163 μm long and having a spherical diameter of 374 μm. The cell's chloroplasts actually change the cell's shape as they move closer to the cell's wall in daytime and retract towards the nucleus at night. P. fusiformis will only photosynthesize during daylight hours and mostly produce bioluminescence during night because of their circadian rhythm which controls both processes. Bioluminescence Bioluminescence occurs when an organism emits light through a chemical reaction with the majority of the world's bioluminescent organisms living in the ocean. The production of bioluminescence by P. fusiformis is thought to be a defense mechanism that startles grazers which would otherwise eat them In P. fusiformis bright blue light is produced through the reaction of the enzyme luciferase and protein-like compound luciferin in the cell's plasma membrane. and the genome of P. fusiformis contains shared common origin with other dinoflagellates that contain the luciferase enzyme. ==Life cycle==

Pyrocystis fusiformis has a full life cycle of approximately 5–7 days and reproduces asexually. ==Ecology==

Phytoplankton including P. fusiformis play a large role in global carbon cycling by fixing carbon Phytoplankton also form the basis of the marine food chain and are preyed upon by various organisms, such as grass shrimp, mosquito fish, mysids, It is estimated that P. fusiformis occurs most frequently at a depth of 60 and 100 meters in marine waters, tropical and subtropical bays and also oligotrophic waters, In oligotrophic water, nitrogen (N) is a limiting nutrient for phytoplankton growth. Nitrate (NO−3) and ammonium (NH+4), both inorganic form of nitrogen, are most often taken up by phytoplankton and are necessary for growth and metabolic processes. ==Human interest==

Pyrocystis fusiformis is interesting to humans as a natural phenomenon to observe in the ocean, in addition to being easily cultivated in a controlled environment at home and in classrooms for study. P. fusiformis is commonly grown for science and art projects. Because P. fusiformis is important to scientific study as it only flashes when agitated and could be utilized in flow visualization to help spot differences in water flow or disruption of water by predators. Her large scale photographs demonstrate the blue color that P. fusiformis produces when agitated. Working with scientists at the Scripps Institution of Oceanography, Blumenfeld photographs P. fusiformis in order to "activate a dialogue about our natural environment and our relationship to it." In 2025, Dutch fashion designer Iris van Herpen designed a dress using 125 million P. lunula. ==References==