Editing Dinoflagellate (section)

=== Pigments in dinoflagellates ===
Dinoflagellates possess a distinctive suite of photosynthetic pigments that allow them to survive and grow in a variety of aquatic environments. Like other phytoplankton, many dinoflagellates contain chlorophyll a and chlorophyll c, which are essential for photosynthesis and light energy capture.<ref>{{Cite book |last1=Jeffrey |first1=S. W. |url=https://figshare.utas.edu.au/articles/chapter/Microalgal_classes_and_their_signature_pigments/23056505 |title=Microalgal classes and their signature pigments |last2=Wright |first2=Simon |last3=Zapata |first3=M. |date=2011-01-01 |publisher=University of Tasmania |isbn=978-0-511-73226-3 |language=en}}</ref> However, unlike green algae and higher plants, they lack chlorophyll b. Instead, they utilize chlorophyll c2, which is more efficient for absorbing blue-green light, making them well adapted to low-light or deeper water conditions.<ref>{{Cite journal |last1=Schlüter |first1=L |last2=Møhlenberg |first2=F |last3=Havskum |first3=H |last4=Larsen |first4=S |date=2000 |title=The use of phytoplankton pigments for identifying and quantifying phytoplankton groups in coastal areas:testing the influence of light and nutrients on pigment/chlorophyll a ratios |journal=Marine Ecology Progress Series |language=en |volume=192 |pages=49–63 |doi=10.3354/meps192049 |bibcode=2000MEPS..192...49S |s2cid=56561696 |issn=0171-8630}}</ref> These pigments, along with carotenoids, contribute to the characteristic coloration of dinoflagellates, which can range from golden-brown to red.

A unique pigment in dinoflagellates is peridinin, a specialized carotenoid that plays a key role in light harvesting and energy transfer to chlorophyll a.<ref>{{Cite journal |last=Takaichi |first=Shinichi |date=2011 |title=Carotenoids in algae: distributions, biosyntheses and functions |journal=Marine Drugs |volume=9 |issue=6 |pages=1101–1118 |doi=10.3390/md9061101 |doi-access=free |issn=1660-3397 |pmc=3131562 |pmid=21747749}}</ref> Peridinin is highly efficient in capturing blue light, which penetrates deeper into the water column, giving many dinoflagellates a competitive advantage in stratified or turbid environments.<ref>{{Cite journal |last1=Jiang |first1=Jing |last2=Zhang |first2=Hao |last3=Kang |first3=Yisheng |last4=Bina |first4=David |last5=Lo |first5=Cynthia S. |last6=Blankenship |first6=Robert E. |date=July 2012 |title=Characterization of the peridinin-chlorophyll a-protein complex in the dinoflagellate Symbiodinium |journal=Biochimica et Biophysica Acta (BBA) - Bioenergetics |volume=1817 |issue=7 |pages=983–989 |doi=10.1016/j.bbabio.2012.03.027 |issn=0006-3002 |pmc=3947849 |pmid=22497797}}</ref> Additionally, dinoflagellates contain other carotenoids such as diadinoxanthin and dinoxanthin, which play important roles in photoprotection by dissipating excess light energy and preventing oxidative stress under high irradiance.<ref>{{Cite journal |last1=Lavaud |first1=Johann |last2=Rousseau |first2=Bernard |last3=van Gorkom |first3=Hans J. |last4=Etienne |first4=Anne-Lise |date=2002-07-01 |title=Influence of the Diadinoxanthin Pool Size on Photoprotection in the Marine Planktonic Diatom ''Phaeodactylum tricornutum'' |journal=Plant Physiology |language=en |volume=129 |issue=3 |pages=1398–1406 |doi=10.1104/pp.002014 |pmid=12114593 |pmc=166533 |issn=1532-2548 }}</ref>  These pigments are necessary for photoacclimation, allowing dinoflagellates to survive under fluctuating light conditions.

Not all dinoflagellates rely solely on photosynthetic pigments for energy. Many species are heterotrophic or mixotrophic, meaning they can acquire nutrients through both photosynthesis and predation.<ref>{{Cite web |title=Acquired phototrophy in aquatic protists |url=https://www.researchgate.net/publication/242489569 |archive-url=https://web.archive.org/web/20180701083507/https://www.researchgate.net/publication/242489569_Acquired_phototrophy_in_aquatic_protists |archive-date=2018-07-01 |access-date=2025-02-16 |website=ResearchGate |language=en |url-status=live }}</ref> Symbiotic dinoflagellates, such as Symbiodinium, play a important ecological role by forming mutualistic relationships with corals, where their pigments drive photosynthesis and energy production that sustain coral reef ecosystems.<ref>{{Cite journal |last1=Stat |first1=Michael |last2=Carter |first2=Dee |last3=Hoegh-Guldberg |first3=Ove |date=2006-09-27 |title=The evolutionary history of Symbiodinium and scleractinian hosts—Symbiosis, diversity, and the effect of climate change |url=https://www.sciencedirect.com/science/article/abs/pii/S1433831906000035 |journal=Perspectives in Plant Ecology, Evolution and Systematics |volume=8 |issue=1 |pages=23–43 |doi=10.1016/j.ppees.2006.04.001 |bibcode=2006PPEES...8...23S |issn=1433-8319}}</ref> The unique pigment composition of dinoflagellates also contributes to large-scale phenomena such as harmful algal blooms and red tides, where high concentrations of pigmented cells cause dramatic discoloration of coastal waters and can produce toxic effects.<ref>{{Cite journal |last1=Anderson |first1=Donald M. |last2=Cembella |first2=Allan D. |last3=Hallegraeff |first3=Gustaaf M. |date=2012 |title=Progress in understanding harmful algal blooms: paradigm shifts and new technologies for research, monitoring, and management |journal=Annual Review of Marine Science |volume=4 |pages=143–176 |doi=10.1146/annurev-marine-120308-081121 |issn=1941-1405 |pmc=5373096 |pmid=22457972|bibcode=2012ARMS....4..143A }}</ref>