Dinoflagellates

• All are unicellular
• -          Store food as starch
•  
• Are uninucleated
•  

Have permanently condensed nuclei (mesokaryotic)

• Some are bioluminescent
• Grooves around it for the flagella
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• Lack a photosynthetic apparatus; absorb organic compounds; feed from a peduncle
•  
• In unfavorable conditions, they produce nonmotile cysts
•  
• Some are photosynthetic; others are heterotrophic

• Roll around
• Tensile like flagella

Mostly marine; some freshwater; warmer is preferred, but can live in cold

• -          Some don’t have a cell wall but a thin structure called the periplast
• -          Others have a cell wall that is to the inside of the membrane; armored; it has grooves that the flagella sit in

Chlorophylls a and c and several carotenoids (peridinin)

• Asexual
• During mitosis, the nuclear membrane persists; the chromosomes attach to it as cytoplasmic channels split the cell
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• Cell wall gets donated to two daughters, who must regenerate the other half
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• Sexual reproduction is rare

Problems:-  red tide

Diarrhetic Shellfish poisoning: caused by diophysis spp; okadaic acid 

Neurotoxic shellfish poisoning: caused by brevetoxin from Gymnodinium 

Paralytic shellfish poisoning: caused by alexandrium, gymnodinium, and pyrodium- 12-18 different neurotoxin

Ciguatera Fish Poisoning: gambierdiscus toxicus; cugatoxin and maitotoxin 

Release of endo- and exotoxins

Responsible for the photosynthetic protductivity that makes possible the growth of coral reefs