How long can phytoplankton live?

Answer 1

The life span of plankton generally depends on their size. Most of the

larger animal plankton live several months, but some may live more

than a year.

For the one-celled plankton, it isn't possible to give a life span, because

they reproduce by dividing in two, so how old is a cell? However, the

one-celled plankton divide every few hours to every few days,

depending on the species and the growth conditions. Edited in 2009.

Answer 2

A few days but they divide rapidly.