Sperm whale . Myoglobin, which stores oxygen in muscle tissue, is much more abundant than in terrestrial animals. The blood has a high density of red blood cells, which contain oxygen-carrying haemoglobin. The oxygenated blood can be directed towards only the brain and other essential organs when oxygen levels deplete. The spermaceti organ may also play a role by adjusting buoyancy (see below). The arterial retia mirabilia are extraordinarily well-developed. The complex arterial retia mirabilia of the sperm whale are more extensive and larger than those of any other cetacean. Atop the whale's skull is positioned a large complex of organs filled
Bowhead whale whales" were confirmed to be from bowhead whales. The bowhead whale has a large, robust, dark-coloured body and a white chin/lower jaw. The whale has a massive triangular skull, which it uses to break through the Arctic ice to breathe. Inuit hunters have reported bowheads surfacing through of ice. The bowhead also has a strongly bowed lower jaw and a narrow upper jaw. Its baleen is the longest of that of any whale, at , and is used to strain tiny prey from the water. The bowhead whale has paired blowholes, at the highest point of the head, which can