The Ross seal is the rarest and the least known of the four Antarctic seals. It was discovered and named during the expedition led by Sir James Clark Ross during 1839-43.
Ross was an accomplished Arctic explorer who had reached the North Magnetic Pole in 1831. During the early 1830s there was much discussion in learned circles in England that terrestrial magnetism needed to be more fully investigated, particularly in the southern hemisphere. An expedition was arranged and Ross was chosen to lead it. He was accompanied by a talented team of scientists which included Joseph Dalton Hooker. After establishing magnetic observatories at St Helena, Cape of Good Hope and Hobart, Ross, with his two ships Erebus and Terror, proceeded south to make an attempt to reach the South Magnetic Pole.
The Ross seal inhabits heavy pack ice, an area until recently out of the reach of most scientists. Of those specimens that have been studied the largest was a male weighing 216 kilograms and measuring 208 centimetres: this compares with a Weddell seal weighing 400-500 kilograms and measuring 297-329 centimetres. The Ross seal has a short snout with particularly large eyes which it is believed indicate it is a deep diver. Its principal diet is squid. Its body markings are distinctive with longitudinal striping extending back from the head. It also has a distinctive siren-like call and if approached will raise its head and arch its back in a characteristic posture.
Specimens of the Emperor penguin were also collected and scientifically described for the first time by the Ross expedition.