Part 3 of “Name that Poisonous Beast” is ocean-themed.

Name this poisonous beast!



And it’s floaty colleague:



  • A) Barracuda contaminated with Ciguatoxin (from Gambierdiscus toxicus, a dinoflagellate)
  • Ciguatera poisoning: activates voltage-dependent sodium channels
    • Reef fish (barracuda, amberjack, moray eel, grouper, red snapper, sea bass, spanish mackeral)
      • Small fish eat contaminated algae—>big reef fish eat small fish—>ciguatoxin is concentrated
      • Tasteless, odorless and heat resistant
    • Symptom onset: 15 minutes to 24 hours; generally 6-12 hours
      • GI: abd pain, n/v/d, painful defecation (appears first)
      • Neuro: perioral paresthesia, temperature dysesthesias, dental pain, pruritis, blurred vision, metallic taste, dysuria (within hours to 3 days, may last months)
        • Less common: ataxia, hallucinations, resp paralysis, coma
      • CV: bradycardia, hypotension, pulm edema (within 2-5 days)
    • Treatment: largely supportive and symptomatic
      • Activated charcoal, antihistamines, tylenol/NSAIDs (avoid opiates/barbs)
      • Mannitol with IV hydration for neuro sx (reverses opening of sodium channels)
      • Consider amitriptyline/gabapentin
    • For 6 months after recovery, avoid fish, shellfish, alcohol, nuts, nut oils
  • B) Box jellyfish [Cnidaria] (Chironex fleckeri)
    • Local effects: painful erythema—>linear urticaria (mins-hours)
      • Possible full-thickness necrosis (1-2 weeks)
    • Systemic effects: headache, n/v, muscle spasm, fever, syncope
      • Severe: resp distress/pulm edema, tachycardia, AKI, MI, cardiac arrest
    • Lrukandji syndrome (minor box jellyfish): back/chest/abd pain, n/v, diaphoresis, headache, tachycardia, hypertension, agitation, possible MI/pulm edema
    • Prehospital treatment:
      • Inactivate nematocytes w/vinegar or acetic acid
      • Carefully remove live tentacles (detached tentacles can still envenomate for several hours)
    • ED treatment: supportive care: wound care, tetanus, antihistamines, consider topical anesthetics and corticosteroids
      • Box jellyfish antivenom if cardiac arrest, hypotension, dysrhythmia, coma, resp distress, dysphagia, dysarthria, severe pain refractory to treatment
        • Dose: 1 ampule diluted 1:10 with NS IV; 6 ampules in arrest; IV Mag if unsuccessful
    • Lrukandji syndrome tx: nitroglycerin/phentolamine for htn, opiates, benzos; no available antivenom