Final answer:
Paralytic shellfish poisoning symptoms include numbness, muscle weakness, respiratory difficulties, and gastrointestinal distress, caused by neurotoxins from algal blooms consumed by shellfish.
Step-by-step explanation:
The most common symptoms of paralytic shellfish poisoning are numbness or tingling in the face, arms, and legs, muscle weakness, difficulty breathing, and nausea and vomiting. These symptoms reflect the toxin's impact on the nervous system, which can lead to neurological problems in humans. The severity of symptoms can vary, and in some cases, they can be life-threatening due to complications such as respiratory failure.