Done by Antar Sarkar, Faculty of Fisheries, CVASU

1. WELCOME
Topic: Shellfish Poisoning
Prepared by: Antar Sarkar
Faculty of Fisheries
CVASU

2. What is Shellfish Poisoning?
Contaminated/ Uncooked Toxin Containing Shellfish
Consumed by Human
Causing Adverse Symptoms

3. How It Occurs?
 Shellfish poisoning can occur after eating clams, mussels, oysters,
scallops, cockles, starfish, and crustaceans contaminated by toxins.
 Shellfish accumulate the toxins via feeding toxic dinoflagellates in
their digestive organs and soft tissues, apparently without harm to
themselves.
 It is common during red tides, when sea waters turn a reddish
color because of the presence of large numbers of dinoflagellates
 These dinoflagellates produce at least 12 toxins, which are
tetrahydropurines and are heat and acid stable.

4. How It Reaches to Human?

6. How It Affects Human?

7. HAB and Shellfish Poisoning
Eutrophication
Harmful Algal Bloom
Consumed by Shellfish
Toxicity on Consuming Shellfish

8. Paralytic Shellfish Toxin
(PSP)
Diarrhoeic Shellfish Toxin
(DSP)
Amnesic Shellfish Toxin
(ASP)
Neurotoxic Shellfish Toxin
(NSP)
Azaspiracid Shellfish Toxin
(AzSP)
Five Groups of Toxins

9. Paralytic Shellfish Toxin
Diarrhoeic Shellfish Toxin
Amnesic Shellfish Toxin
Neurotoxic Shellfish Toxin
Azaspiracid Shellfish Toxin
Paralytic Shellfish Poisoning
Diarrhoeic Shellfish Poisoning
Amnesic Shellfish Poisoning
Neurotoxic Shellfish Poisoning
Azaspiracid Shellfish Poisoning

10. Paralytic Shellfish Poisoning
 Organism Containing: Mostly bivalve mollusks
including mussel, clams, scallop, cockles.
Gastropod, whelks and some lobster also.
 Causative Agent: Dinoflagellates and blue-
green algae Alexandrium tamarensis, A.
fraterculus, A. minutum, A. catenella,
Pyrodinium bahamense, Gymnodinium
catenatum, Aphanazomenon flos-aquae

11. Paralytic Shellfish poisoning
Trade Name: STX (Saxitoxin)
Symptoms:
• Slight tingling or numbness to complete
respiratory paralysis.
• In fatal cases, respiratory paralysis occurs within 2
to 12 hours food.

12. Amnesic Shellfish Poisoning
 Organism Containing: Cultured blue mussel (Mytilus edulis),
Razor clams (Siliqua patula), Soft shell clams (Mya arenaria),
Bay scallop (Argopecten iradians), spiny scallop (Chlamys
hastate), water fowl, cormorants, benthic crustaceans and
anchovies.
 Causative Agent: Red algae (Chondria baileyana, C.armata,
Alsidium corallinum), Diatoms (Pseudo-nitzschia pungens,
P.pseudodelicatissima, P.australis, P.seriata, P.multiseries,
P.turgidula)

13. Amnesic Shellfish Poisoning
Trade Name: DAP (Domoic Acid Poisoning)
Symptoms:
 Headaches, abdominal pain, cramping, nausea, vomiting,
and diarrhea within 30 minutes to 24 hours.
 Severe toxicity can cause permanent short-term memory
loss, seizures, coma, or shock over the next 48 hours.
 CNS toxicity is the major concern.

14. Diarrhoeic Shellfish Poisoning
 Organism Containing: Mussels (Mytilus edulis),
Scallop (Patinopecten yessoensis), Clams (Tapes
japonica), Cod fish in cages fed with toxic
mussel.
 Causative Agent: Dinoflagellates (Dinophysis
acuminate, D. acuta, D. sacculus, D. norvegica, D.
tripus, Prorocentrum fortii, P. lima, P.micans,
Protoperidinium spp.)

15. Diarrhoeic Shellfish Poisoning
Trade Name: DAP (Domoic Acid Poisoning)
Symptoms:
• Diarrhea is the most common symptom, closely
followed by nausea (80%) and vomiting with onset
30 minutes to 12 hours from ingestion.
• Complete clinical recovery is seen even in severe
cases within 3 days

16. Azaspiracid Shellfish Poisoning
 Organism Containing: Contaminated Irish
mussels, mussels and oyster.
 Causative Agents: Dinoflagellate
(Protoceratum crassipes, Protoperidinium)

17. Azaspiracid Shellfish Poisoning
Trade Name: Azaspiracid
Symptoms:
• Syndrome is very similar to diarrheic shellfish
poisoning (DSP)
• Main symptoms appearing after a few hours from
consumption and including diarrhea, vomiting, and
stomach cramps

18. Neurologic Shellfish Poisoning
 Organism Containing: Oyster (Crassostrea gigas),
cockles (Austrovenus stutchburyi), Greenshell
mussels (Perna canaliculus), the copepod (Temora
turbinate)
 Causative Agents: Marine dinoflagellates
(Gymnodinium breve), Raphidophytes (Chattonella
antiqua, C. marina, Fibrocapsa japonica)

19. Neurologic Shellfish Poisoning
Trade Name: Brevetoxin
Symptoms:
• Mild to moderate nausea, vomiting and diarrhea.
• Numbness and tingling in the lips, mouth and face.
• Ataxia, overall loss of coordination, and partial limb
paralysis may also occur.
• The reversal of hot and cold sensation.
• Slurred speech, headache, pupil dilation, throat
tightness, chest heaviness and overall fatigue are also
commonly reported.

20. Prevention
CookingDepuration
Avoiding Eating as Raw
Evisceration
Processing
Eating Packaged Shellfish
Preventing Eutrophication

21. THANKS
“It is Good for Nothing to be
a Colorful Shellfish Having
Toxins Inside”