In five kingdom scheme of classification, the algae, together with the protozoa, belong to Kingdom Protista. They are distinct from the protozoa by being photosynthetic. The algae are further grouped into various phyla: Euglenophyta (euglenids), Chrysophyta (diatoms), Dinoflagellata (dinoflagellates), Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae). The Cyanophyta or blue-green algae, which are prokaryotic organisms, are traditionally included in this group but in modern classification, they are now grouped together with bacteria under Kingdom Monera. It should be noted, however, that the taxonomic classification of organisms is bound to change as further studies of the species would lead to newer system of classification, such as that in The NCBI taxonomy database.1
Phylym Dinoflagellata is comprised of the dinoflagellates. Dinoflagellates are photosynthetic organism characterized by having two flagella lying in grooves in an often elaborately sculptured shell or pellicle that is formed from plates of cellulose deposited in membrane vesicles. Dinoflagellates have bizarre shapes because of their pellicle. They are described as mesokaryotic. Their nuclear membrane persists during mitosis. Their nucleus is also a distinctive feature. Referred to as dinokaryon, their nucleus is characterized by the chromosomes that are fibrillar in appearance and are more or less continuously condensed. And in stead of histones, dinoflagellates have a family of nuclear proteins that are probably of viral origin that are bound to DNA.
Many of them are associated with red tide phenomenon. That is when certain dinoflagellate species grow at a rate faster than normal. A toxin referred to as dinoflagellate toxin is a potent neurotoxin that impairs the synthesis or the release of acetylcholine.
1 The NCBI taxonomy database. Retrieved from .