More Behavior Observations
The pair in my 15 gallon are proving to be more interesting to observe than the three in the 45 snice I can only find the one in the 45 that has taken the mother's brooding den at the front of the tank.
I have modified the outdoor Flourex light (65 Watt, 6500K) by adding 3 layers of red transparent film and leave the light on 24/7. This gives very good viewing light but poor lighting for photography.
The "female" was finally viewable (I saw more than just arms) but only stayed out a short time after I sat down to observe the tank.
The "male" continued to exhibit interesting behavior. He was again out in the open but had his first arm over his eyes (typical Merc posture). Thinking he may be showing hunger, I offered a small live crab by hand. He disappeared into the LR and proceeded to systematically jet out the carcass of the last crab he had eaten. First the legs
flew from the den then the empty body casing but he did not take the fresh crab. OK, maybe he wanted shrimp (there are several live shrimp in the tank) so I hand presented a shore shrimp. He touched and held the shrimp then
pushed it back into my fingers when I released it. I continued to offer it and he insisted on pushing it back into my hand (he did not use his siphon and was definitely pushing it into my fingers, not just away from the den area). I then offered it to the extended arm of the "female" who took it immediately.
The male continues to
twirl the ends of multiple arms when he sits in the open and he sees movement outside the tank.
http://s116.photobucket.com/albums/...action=view¤t=ArmWiggleAndBobbing01.flv
In the ID request section, Christine Huffard (Mucktopus) provided a link to one of her published studies on A. Aculeatus:
http://mollus.oxfordjournals.org/cgi/reprint/eym015?ijkey=KKEaa79OOS387DW&keytype=ref
and mentions male guarding behavior when a male and female pair of octopuses live within touching distance. I am wonder if this is what I am seeing.
Addendum:
I noticed after posting that I can see a larger sucker near the base of the first arm. The photo is ugly but you can see the enlargement:
http://i116.photobucket.com/albums/o6/dwhatley/Octopus/MaleEnlargedSuckerCrop.jpg
I also shot another video of the arm movement where you can see the full mantle. I missed the interaction with the serpent. The octopus will rapidly swipe at shrimp to chase them away but gently pushes away the arms of the serpent star. If the serpent insists, the octopus continues to gently relocate the arm until the star accepts the new position. His lack of interest in eating today is a little frightening, surely we are not already approaching the end.
http://s116.photobucket.com/albums/o6/dwhatley/Octopus/?action=view¤t=FullMonty.flv
