I got surprised by that too, and while comparing its size to the next organism (Tardigrade) I learned that every member of the same species of tardigrades has the exact same number of cells [1], which was even more surprising for me:

> Eutelic organisms have a fixed number of somatic cells when they reach maturity, the exact number being relatively constant for any one species. This phenomenon is also referred to as cell constancy. Development proceeds by cell division until maturity; further growth occurs via cell enlargement only.

[1] https://en.wikipedia.org/wiki/Eutely