Question

Toxin responsible for Paralytic shellfish poisoning is

• A. Saxitoxin
• B. Brevetoxin
• C. Okadaic acid
• D. Domoic acid

Hint:

Remember the diagnostic pairings of shellfish poisoning toxins:
Saxitoxin $\rightarrow$ Paralytic (PSP).
Domoic Acid $\rightarrow$ Amnesic (ASP).
Okadaic Acid $\rightarrow$ Diarrhetic (DSP).
Brevetoxin $\rightarrow$ Neurotoxic (NSP).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Harmful Algal Blooms (HABs), often called red tides, produce potent biotoxins that can accumulate in the tissues of filter-feeding bivalve molluscs (like mussels, clams, and oysters).
When humans ingest these contaminated shellfish, it leads to severe foodborne poisoning syndromes.

Step 2: Detailed Explanation:
Let us analyze the specific toxins and their associated poisoning syndromes:
Brevetoxin is produced by the dinoflagellate Karenia brevis and is responsible for Neurotoxic Shellfish Poisoning (NSP).
Okadaic acid is produced by Dinophysis and Prorocentrum species, causing Diarrhetic Shellfish Poisoning (DSP).
Domoic acid is an amino acid produced by the diatom Pseudo-nitzschia, causing Amnesic Shellfish Poisoning (ASP) due to neurological damage in the hippocampus.
Saxitoxin is a highly potent neurotoxin produced primarily by marine dinoflagellates belonging to the genera Alexandrium, Gymnodinium, and Pyrodinium.
Filter-feeding shellfish accumulate saxitoxin in their digestive glands and muscular tissues without being harmed themselves.
If humans consume these contaminated shellfish, saxitoxin acts as a selective sodium channel blocker, preventing the transmission of nerve impulses.
This leads to rapid neurological symptoms, including tingling, numbness, and potential respiratory paralysis.
This clinical syndrome is known as Paralytic Shellfish Poisoning (PSP).

Step 3: Final Answer:
The toxin responsible for Paralytic shellfish poisoning is Saxitoxin.