[2] The most distinctive feature of polykrikoids is their formation of multinucleate "pseudocolonies" consisting of an even number of subunit zooids.

In particular, an extrusome complex of two organelles called the nematocyst and taeniocyst is considered a synapomorphy for Polykrikos.

[1][3] Molecular phylogenetics studies suggest some inconsistency in the taxonomy of this group, particularly in the assignment of species to one of the two genera.

[6] Some species, such as P. kofoidii, are of scientific interest due to their status as predators of other dinoflagellates, a behavior that is significant in the regulation of algal blooms.

[11] The family demonstrates a complex evolutionary history indicating multiple instances of loss of photosynthetic plastids in different lineages.