Question: How many different shapes of plankton have you discovered so far?

Russell Arnott answered on 8 Mar 2019:

Some of the plankton I work with are small and round; some are like two big spheres with a ballet tutu round the middle; some are like small rods; some a like a hemisphere stuck to a cone; some are discs; some are cylinders; some grow in long chains all stuck together with spines sticking out of them…