红海羽藻藻类群落，半月触发鱼在上方游动

y of red sea plume algae (Asparagopsis taxiformis) on a shallow Andaman Sea reef, its fronds forming a patch of reef macroalgae, also called limu kohu, this native Indo-Pacific alga produces a reactive compound thought to deter grazing fish, reinforced by blue warning colouration at its growth tips. Reef algae like this quietly shape fish feeding behaviour on Indo-Pacific reefs. One halfmoon triggerfish (Sufflamen chrysopterum) swims above. 4K, wide angle, vertical, medium shot, scuba diver POV. Andaman Sea, Krabi Province, Thailand.