Many plankton species migrate from the deep ocean to the surface and back.
Single-celled phytoplankton, lacking appendages, face difficulties in this migration.
Researchers studied Pyrocystis noctiluca, a bioluminescent phytoplankton.
Phytoplankton are generally denser than seawater, requiring strategies to stay afloat.
P. noctiluca cells can control their density to adjust their position in the water column.
Inflation Strategy for Buoyancy
Researchers discovered two distinct sizes of P. noctiluca cells in a bloom.
Videos revealed that the cells undergo significant inflation.
The team used a gravity machine to simulate ocean depths and test the effects of inflation.
Inflated cells were less dense than seawater, allowing them to float upward.
Inflation is a natural part of the phytoplankton's cell cycle.
A vacuole in the cell fills with fresh water, causing the cell to swell.
Inflated daughter cells float upward due to their reduced density.
After reaching the surface and growing, the cells become heavier and sink, repeating the cycle.
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