I just wanted to know if anybody knows about this subject. Is there any indication that big invertebrates like Architeuthis or Mesonychoteuthis have a thermal benefit of their big body size? Or is there actually any indication that any cold-blooded aquatic animal which is not like great whites of swordfish able to produce much metabolic heat, could maintain body temperatures significiantly over the surrounding water as a result of big body size? Actually I don´t think so, but I would be very interested to know what you think about it. I would suppose that any aquatic animal which has a comparably low metabolism and no thermoisolation like a fat layer or fur would always have nearly 100% the same overall body temperature as the water, and there is no reason for such an animal to evolve bigger sizes for a better temperature regulation.