After a few moments, remove the compresses and observe the results. What the students have succeeded in demonstrating is the recommended treatment for a marine envenomation. Most fish venoms, being proteins, are readily denatured by the application of heat. In much the same way the egg white solidifies when heated, venoms coagulate under heat treatment. This coagulation inhibits their circulation under the skin, in the case of punctures by spines or injections by fangs, and allows their ready removal in the case of surface stings such as delivered by jellyfish and corals.
Venomous animals are common among insects, fishes, amphibians, and reptiles.
There are no venomous birds, and only one venomous mammal-the duckbill platypus of Australia. Assign students into groups for each of the four groups of animals mentioned in the first sentence. Let each student choose an example or examples from these groups to report on. Have students consider the potency of venoms, how the animals deliver them, and what their purposes are.