Yep. I am not so much surprised by the news as the fact that it is news.
Of course a creature sensitive to light infiltration and dissolved gasses has a way to control buoyancy. Flagella would burn too much energy if that was the sole mechanism. Now we know. Or think we do.
When you make some kind of porridge by boiling either ground cereal seeds (i.e. some kind of coarse cereal meal, e.g. cornmeal or semolina) or whole cereal seeds (e.g. of rice or wheat or barley), they will absorb a quantity of water of at least four times the mass of the cereals. Therefore the cooked food will be much more voluminous than the original cereals.
Both Pyrocystis noctiluca and the boiled cereal seeds increase their volume many times by absorbing water, but Pyrocystis noctiluca keeps the water in internal vacuoles, while in the boiled seeds the water is incorporated in their starch granules. All starchy seeds absorb water when boiled, but most of them do not absorb so much water as the cereal seeds, so their increase in volume is lower.
"Users named Supermacho, deposit commas in title, but 'fix' is questionable."
Dividing the subject from the verb with a comma--even when the upcoming verb could be confused with a noun--makes it like a stilted old cost-conscious telegram where the STOP isn't being spoken. Ex:
"Egrets, fish for most of their food, say biologists."
It can also create new confusion, like this example of either cramped living arrangements or an immediate television event:
"Florida couple, live in studio, with alligators."
_____
I'd rather prep the reader to anticipate a verb:
"Plankton [may] balloon to six times size in newly discovered mode of oceanic travel"
No, that is absolutely not a fix. The original is grammatically correct, albeit using "balloon" as a verb. Your version is simply wrong. There is no parenthetical subclause here and your attempt to insert one is incorrect.
Supplementary Video 2: https://www.youtube.com/watch?v=uPZe_UDtseM