Question

write short notes on Dinoflagellates?​

Answer 1

Answer:

terms of number of species, dinoflagellates are one of the largest groups of marine eukaryotes, although this group is substantially smaller than diatoms.[8] Some species are endosymbionts of marine animals and play an important part in the biology of coral reefs. Other dinoflagellates are unpigmented predators on other protozoa, and a few forms are parasitic (for example, Oodinium and Pfiesteria). Some dinoflagellates produce resting stages, called dinoflagellate cysts or dinocysts, as part of their lifecycles, and is known from 84 of the 350 described freshwater species, and from a little more than 10% of the known marine species.[9][10] Dinoflagellates are alveolates possessing two flagella, the ancestral condition of bikonts.

About 1,555 species of free-living marine dinoflagellates are currently described.[11] Another estimate suggests about 2,000 living species, of which more than 1,700 are marine (free-living, as well as benthic) and about 220 are from fresh water.[12] The latest estimates suggest a total of 2,294 living dinoflagellate species, which includes marine, freshwater, and parasitic dinoflagellates.[2]

A rapid accumulation of certain dinoflagellates can result in a visible coloration of the water, colloquially known as red tide (a harmful algal bloom), which can cause shellfish poisoning if humans eat contaminated shellfish. Some dinoflagellates also exhibit bioluminescence—primarily emitting blue-green light. Thus, some parts of the Indian Ocean light up at night giving blue-green light.

Answer 2

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Dinoflagellates are unicellular protists comprising two flagella. Dinoflagellates are mostly marine plankton, but also found in freshwater habitats. Photosynthetic dinoflagellates form one of the largest group of eukaryotic algae apart from diatoms.

Dinoflagellates have characteristics of both plants and animals. There are more than 4500 species of dinoflagellates. Some are photosynthetic autotrophs and some species are heterotrophs, which get their nutrients by phagocytosis. They can be parasitic and endosymbiont to red algae.

Dinoflagellates were classified under kingdom Protista and phylum Dinoflagellata. Some scientists have kept dinoflagellates in the division Pyrrophycophyta (meaning- fire plants).

Dinoflagellates are kept in the supergroup Chromalveolata, they seem to have originated from the secondary symbiosis of red algae. The group Alveolata is characterised by the presence of similar ribosomal DNA sequence and alveoli, which is a flattened vesicle present inside the plasma membrane.