The parasitic dinoflagellate "Hematodinium" however lacks a plastid entirely. The toxic dinoflagellate "Dinophysis acuta" acquire chloroplasts from its prey. Many nassellarian radiolarians house dinoflagellate symbionts within their tests. About half of living dinoflagellate species are autotrophs possessing chloroplasts and half are nonphotosynthesising heterotrophs. There were also dinoflagellate and Zygnemataceae algae, as well as numerous pollen and spore taxa. Previously the genus contained also a large number of marine dinoflagellate species. In addition to this dinoflagellate, coral also form relationships with bacteria, archae and fungi. The term specifically refers to blooms of a species of dinoflagellate. The genus Ceratium is restricted to a small number (about 7) of freshwater dinoflagellate species. The N-terminal domain is conserved between dinoflagellate luciferase and luciferin binding proteins (LBPs). Maitotoxin (or MTX) is an extremely potent toxin produced by "Gambierdiscus toxicus", a dinoflagellate species. The biostratigraphical application of dinoflagellate cysts has been thoroughly studied. This type of bloom is caused by another species of dinoflagellate known as "Alexandrium fundyense". The structure of the dinoflagellate luciferase catalytic domain has been solved. Rather, this has been attributed, hypothetically, to the rampant retroposition found in dinoflagellate genomes.