The bottom arm in this view is the hectocotylus arm (right arm #3) in an Enteroctopus dofleini male of about 50 cm arm spread. Arm #4 is shown above for comparison.
This view of a dissected E. dofleini shows the salivary glands. The salivary glands of many octopus secrete poison which can be excreted through the salivary papilla in the mouth and used to subdue prey.
This dogfish (Squalus acanthias) skeleton was found outside an octopus den in 2005 by divers. Finders include Jon Mayberry (L), Kirt Onthank (middle), and Nick Marsh