106 DANGEROUS MARINE ANIMALS 



Smooth Washington, or Butter Clam, Saxidomus giganteus 

 (Deshayes) (Fig. 64, Center). Ranges from Sitka, Alaska, to San 

 Francisco Bay, California. 



Common Washington, or Butter Clam, Saxidomus nuttalli Con- 

 rad (Fig. 64, Bottom). Ranges from Humbolt Bay, California 

 to San Quentin Bay, Baja California. 



Medical Aspects. There are three types of shellfish poisoning that 

 are recognized by physicans, they are: (1) Gastrointestinal type — 

 characterized by such symptoms as nausea, vomiting, diarrhea, and 

 abdominal pain. This type usually develops about 10-12 hours 

 after eating the shellfish, and is believed to be caused by bacterial 

 contamination; (2) Allergic type — characterized by redness of the 

 skin, swelling, development of a hive-like rash, itching, headache, 

 nasal congestion, abdominal pain, dryness of the throat, swelling 

 of the tongue, palpitation of the heart, and difficulty in breathing. 

 This type probably results from a sensitivity to shellfish on the 

 part of the individual; (3) Paralytic type — this last type is caused 

 specifically by the dinoflagellate poison present in shellfish. The 

 disease has also been termed clam, mussel, or gonyaulax poisoning 

 (after the scientific name of one of the causative dinoflagellates of 

 the poisoning, namely, Gonyaulax catenella Whedon and Kofoid). 

 The early symptoms are a tingling or burning sensation of the lips, 

 gums, tongue, and face, which gradually spreads elsewhere to the 

 body. The tingling areas later become numb, and movements of the 

 muscles of the body may become very difficult. Other symptoms 

 frequently present are weakness, dizziness, joint aches, increased 

 salivation, intense thirst, difficulty in swallowing. Nausea, vomiting, 

 diarrhea, and abdominal pain are relatively rare. The muscular 

 paralysis may become increasingly severe until death ensues. 



Treatment. There is no specific treatment available; no known 

 antidotes. Evacuation of the gastrointestinal tract should be insti- 

 tuted as soon as possible. Vomiting can be stimulated by swallowing 

 large quantities of salt water, egg white, or by merely placing one's 

 finger down the throat. Alkaline fluids such as ordinary baking 

 soda, are said to be of value since the poison is rapidly destroyed 

 by that medium. Artificial respiration may be required. See a 

 physician at once, if you are fortunate enough to be near a doctor. 



Prevention. The extremely toxic nature of this poison cannot be 

 over-emphasized. One should adhere strictly to local quarantine 

 regulations — they are for your protection. Poisonous shellfish 

 cannot be detected by their appearance, smell, or by discoloration 



