5 public questions tagged with this topic.
Most dinoflagellates possess two flagella. One lies longitudinally, while the other lies transversely in a furrow between the stiff cellulose plates of the cell wall.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Chrysophytes and Dinoflagellates
Red dinoflagellates such as Gonyaulax may multiply so rapidly that the sea appears red. Toxins released by these large populations may kill marine animals such as fishes.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Chrysophytes and Dinoflagellates
Dinoflagellates may appear yellow, green, brown, blue or red depending on the principal pigments present in their cells. Most members are marine and photosynthetic.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Chrysophytes and Dinoflagellates
Dinoflagellates cause harmful algal blooms termed red tides due to rapid proliferation producing discoloration of seawater reddish to brown. Genera like Karenia brevis synthesize brevetoxins, Gonyaulax produces saxitoxins causing paralytic shellfish poisoning and fish kills through neurotoxic effects. Blooms arise from eutrophication and warm stratification, releasing toxins accumulating in filter feeders leading to bioaccumulation. Green tides arise from Ulva, brown tides from Aureococcus. Red tide phenomenon ecologically important due to oxygen depletion, toxin bioaccumulation and human health impacts linked specifically to dinoflagellate overgrowth.
Ref: Campbell Biology 12th ed., Chapter 28: Dinoflagellates Red Tides; NCBI: Marine Harmful Algal Blooms - Dinoflagellate Toxins; NOAA
Dinoflagellates, flagellate alveolates bearing two dimorphic flagella within transverse and longitudinal grooves, can proliferate exponentially forming harmful algal blooms termed red tides due to peridinin carotenoid and high cell densities imparting reddish brown discoloration to seawater. Nutrient enrichment, stratification, and temperature favor blooms, some species produce potent neurotoxins saxitoxin, brevetoxin causing paralytic shellfish poisoning, neurotoxic shellfish poisoning, and massive fish kills detrimental to fisheries. Bioluminescent blooms also occur. Mechanism differs from green tides caused by Ulva and golden tides by Sargassum reflecting dinoflagellate ecology.
Ref: Smayda Dinoflagellate blooms red tides cause; Campbell Biology 11th ed., Chapter 28 Dinoflagellates harmful algal blooms peridinin toxins
