Top 3 smartest marine animals Marine animals are all those animals that live or spend a large part of their lives in water. Taking into account that the oceans represent 71% of the crust of our planet, it seems clear that there are many species of marine animals that exist, although they are also the most affected with respect to extinction, mainly due to fishing. 1° CUTTLEFISH Cuttlefish is a cephalopod from the squid family, its way of moving is more similar to that of a submarine than that of a fish, since cuttlefish have a porous internal bone that allows them to alter their buoyancy by compressing gases, in addition to have a jet of water and ink ejection that they use to escape predators. Undoubtedly an incredible animal, however it is not on this list for its anatomy but rather for its behavior, intelligence and resemblance to our species. To begin with, cuttlefish have one of the most developed eyes and most similar to ours, although they can percei...