Why is this information important?

 

The repertoire of changes in appearance is species specific although some patterns are similar across the class.  In other words, the color, texture and shape components can be used for taxonomy.  The eye spot of Octopus filosus (Figure 2) and the white spots of the Octopus macropus (Figure 3) are species specific.

 

Complex behavioral patterns are used for interspecific interactions.  Octopus cyanea changes its appearance an average 180 times per hour while foraging (Hanlon and Messenger 1998).   Theories of the evolution of cephalopods involve avoiding predation from fish (Packard 1972).  Modern cephalopod density is inversely related to fish density (Ambrose 1991).  Mather and O’Dor (1991) show that cephalopods do not forage optimally – this is also due to predation risk from visual predators.  To avoid becoming dinner for fish, many cephalopods are cryptic and/or nocturnal (Figure 4).   Therefore, appearance is extremely important for the evolution and ecology of these animals.

 

The appearance of a particular individual at a certain age and sex can be used as tools to understand and compare life history, morphology and anatomy.  Cephalopods are developmentally advanced when they hatch  (Figure 5) from eggs (Figure 6).   Some species have offspring of only 1 – 3 mm that are planktonic while others have larger offspring that are benthic  (Figure 7) – morphology indicates life pattern.  Images can also be used to teach anatomy Figure 8 and Figure 9.

 

When people think of intelligence, they almost always think of vertebrates, particularly mammals.  The well developed senses, a brain and variety of behavioral patterns that are readily visible on the skin of cephalopods makes them an ideal out-group for comparative ethological studies.  For example, current research presented at this meeting includes the octopus cognition work by Byrne, Griebel, Kuba, and Meisel and studies of communication in reef squid (Figure 10).