Southern right whale

Like other right whales, the southern right whale is readily distinguished from others by the callosities on its head, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. Its skin is very dark grey or black, occasionally with some white patches on the belly. The right whale's callosities appear white due to large colonies of cyamids (whale lice). It is almost indistinguishable from the closely related North Atlantic and the North Pacific right whales, displaying only minor skull differences. It may have fewer callosities on its head than North Atlantic and more on its lower lips than the two northern species. The biological functions of callosities are unclear, although the primal role has been considered to be for protection against predators. Whale declines may have an effect on barnacle diversity and numbers. An adult female is 15 m (49 ft) and can weigh up to 47 tonnes (46 long tons; 52 short tons), with the larger records of 17.5–18 m (57–59 ft) in length and 80 tonnes (79 long tons; 88 short tons) or up to 90 tonnes (89 long tons; 99 short tons) in weight, making them slightly smaller than other right whales in the Northern Hemisphere. The testicles of right whales are likely to be the largest of any animal, each weighing around 500 kg (1,100 lb). This suggests that sperm competition is important in the mating process. Right whales do not normally cross the warm equatorial waters to connect with the other species and (inter)breed: their thick layers of insulating blubber make it difficult for them to dissipate their internal body heat in tropical waters. However, based on historical records and unconfirmed sightings in modern periods, E. australis transits may indeed occur through equatorial waters. Moreover, a stranding of a 21.3 m (71 feet) long right whale at Gajana, northwestern India in November 1944 was reported, however, true identity of this animal is unclear. The proportion and numbers of molten-coloured individuals are notable in this species compared with the other species in the Northern Hemisphere. Some whales remain white even after growing up. Life span is not clear although whales seem to reach over 100 years old.