 
      
      
Mertensian
              mimicry in tri-colour snakes
          
    Coral snakes, including the Eastern
              Coral snake (Micrurus
              fulvius), are highly venomous, and have a distinctive
            red /  yellow
            / black colour
            pattern that serves as an aposematic (warning)
            signal to advertise this fact. Potential predators avoid
            snakes with this pattern. Other, non-venomous
            snakes, such as the Scarlet King Snake (Lampropeltis
              elapsoides), have evolved a similar red / black
                / yellow colour
            pattern. [NB: It is not obvious why the two species have
            evolved similar but not identical alternating
            patterns. The patterns may be constrained in development].
          
    Notes: Where the two
            species occur in sympatry in the southeastern United States,
            people use the rhyme "Red next to black, friends
                to Jack; Red next to yellow, kill a fellow." New
            teachers in rural schools are often tested with a king snake
            in their desks. 
          
    Biology 101: Remember
            that coral snakes, rattlesnakes, and other snake species are
            venomous, meaning they deliver venom through
            their bites. They are not poisonous,
            meaning you can eat their flesh without danger. Rattlesnakes
            are venomous and not poisonous; not
            unexpectedly, they taste like chicken.  Fugu fish
            of the sushi trade are non-venomous but poisonous.
          
HOMEWORK:
            Identify a species that is both venomous AND poisonous.