Skip to Main Content


Human contact with venomous marine creatures is common and may result in serious injury from biological toxins or mechanical destruction inflicted by the stinging apparatus. Significant morbidity results from envenomation by spiny fish, cone snails, octopi, sea snakes, and several species of jellyfish. Despite significant advances in basic science research regarding the biochemical nature of marine toxins and their mechanisms of action, our knowledge of the pathophysiology related to clinical syndromes in humans and the optimal therapies for human envenomation remain limited. Evidence for effective treatment is primarily derived from in vitro and in vivo animal research without the benefit of controlled human trials. However, current research in toxinology coupled with clinical observations allows the development of cogent treatment guidelines for victims of marine envenomation.




The phylum Cnidaria (formerly Coelenterata) includes more than 9000 species, of which approximately 100 are known to injure humans. They are commonly referred to as jellyfish; however, their phylogenetic designations separate "true jellyfish" and other organisms into distinct classes (Table 120–1; Figure 120–1a). All species possess microscopic cnidae (the Greek knide means nettle), which are highly specialized organelles consisting of an encapsulated hollow barbed thread bathed in venom. Thousands of these stinging organelles, called nematocysts (or cnidoblasts), are distributed along tentacles. A trigger mechanism called a cnidocil regulates nematocyst discharge. Pressure from contact with a victim's skin, or chemical triggers such as osmotic changes, stimulates discharge of the thread and toxin from its casing. Penetration of flesh leads to intradermal venom delivery. Nematocysts of most Cnidaria are incapable of penetrating human skin, rendering them harmless. Cnidaria causing human envenomation, such as the box jellyfish, discharge threads capable of penetrating into the papillary dermis.135

Table Graphic Jump Location
Table 120–1. Characteristics of Common Cnidaria

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessEmergency Medicine Full Site: One-Year Subscription

Connect to the full suite of AccessEmergency Medicine content and resources including advanced 8th edition chapters of Tintinalli’s, high-quality procedural videos and images, interactive board review, an integrated drug database, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessEmergency Medicine

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.