Pyrocystis noctiluca

About Pyrocystis noctiluca:

• It is unicellular marine plankton and produces bioluminescence in response to water movement.
• The bioluminescence takes place in specialised organelles called scintillons. By combining the protein luciferine and the enzyme luciferase light is produced.
• Habitat: It is found in tropical and subtropical seas and oceans.
• It is denser than seawater and should sink. But at the beginning of its life cycle, it swells, reducing its density and traveling up the water column.
• At the end of its seven-day life cycle, the cell then starts to divide into two daughter cells as it sinks.
• When the division is completed, the two newborn cells inflate by filling up with seawater — ballooning to six times their original size in around 10 minutes.
• It is able to navigate vertically upward in the ocean by ballooning to six times its size.
• Photosynthesis: It makes a once-in-a-lifetime trip from about 125 meters deep to about 50 meters, where there’s more of the sunlight that they need to photosynthesize. 

Q1: What is plankton?

The word “plankton” comes from the Greek for “drifter” or “wanderer.” An organism is considered plankton if it is carried by tides and currents, and cannot swim well enough to move against these forces. The most basic categories divide plankton into two groups: phytoplankton (plants) and zooplankton (animals).

Source: Plankton balloon to six times their size to reach ocean surface