The humpback is a rather 'lumpy' animal, and can reach lengths of 17 metres, with the female larger than the male. The head and jaws carry numerous wart-like knobs, which seem to serve no useful purpose, but which may be equivalent to a beard on a human male.
The front edges of the flippers (which are up to 4m long) carry so many of these that they are wavy in outline, as is the deeply notched tail fluke. Their colour is variable: always black above, and dark through to almost white below.
The size and weight is also impressive. A 15m humpback weighs more than 41,000kg, its heart 190kg and its whalebone also 190kg. Yet at times the humpback is seen to leap clear of the water ("breaching"). This may be part of mating behaviour, or simply high spirits. Breaching may also serve to remove barnacles and lice, which often attach themselves to these slow-moving beasts.
They can swim at speeds of up to 27km/h, although normally they swim considerably slower at 4-14km/h.
Though barnacles are a mere discomfort, young humpbacks do have natural enemies and are prey to the killer whale and perhaps the giant squid.Read More: Feeding