Morphological convergence of resting stages of planktonic organisms: a review

In temperate seas, many plankters avoid unfavourable periods by producing resting stages which accumulate in the sediments to form biodiversity banks from which plankton communities are seasonally restored. Most resting stages have typical spiny coverings. This morphology is common across phyla, and even kingdoms, and favours flotation, passive transport, and sensory activity, also opposing both predation and burial into the sediments. Spiny coverings are considered a convergence allowing survival of resting forms.