Oceanic dolphin another indication of animal intelligence. Killer whales have the second largest brain mass of any animal on earth, next to the sperm whale. The brain to body mass ratio in some is second only to humans. Self-awareness is seen, by some, to be a sign of highly developed, abstract thinking. Self-awareness, though not well-defined scientifically, is believed to be the precursor to more advanced processes like meta-cognitive reasoning (thinking about thinking) that are typical of humans. Research in this field has suggested that cetaceans, among others, possess self-awareness. The most widely used test for self-awareness in animals is the mirror
Right whale whales have a distinctive wide V-shaped blow, caused by the widely spaced blowholes on the top of the head. The blow rises above the surface. Right whales have between 200 and 300 baleen plates on each side of their mouths. These are narrow and approximately long, and are covered in very thin hairs. The plates enable the whale to filter feed. The penis on a right whale can be up to – the testes, at up to in length, in diameter, and weighing up to 525 kg (1157 lbs), are also by far the largest of any animal on Earth.