Red tide causing organism belongs to which group of photosynthetic protists?

Solution:Dinoflagellates are responsible for red tide phenomena.

Mechanism of Red Tide:

• Rapid multiplication (algal bloom) of dinoflagellates like Gonyaulax
• Release of saxitoxin and brevetoxin (neurotoxins)
• Water appears red/brown due to pigment concentration
• Causes mass mortality of fish and other marine organisms

Key Dinoflagellate Characteristics:

• Possess two flagella (one longitudinal, one transverse)
• Stiff cellulose plates on cell surface
• Primarily marine habitat
• Exhibit bioluminescence

Common Exam Pitfall: Don't confuse red tide with cyanobacterial blooms, which occur in freshwater and are caused by blue-green algae.