Size: It is the second largest phocid after the elephant seal. The male can weigh up to 300kg and reach 2.80m in length. Females are slightly smaller. The pups are approximately 1m in length at birth.

Fur: They are born with black fur and a white belly patch with a pattern of black spots that is unique to each animal and which is different for males and females (the bottom part is straight in females and curved in males). They retain this fur until approximately two months old. Then, with their first moult, their fur becomes grey and the belly patch is obscured, with only the lateral line visible. Adult females remain grey in colour. Adult males, on the other hand, distinguish themselves from the rest of the population by reverting to their pup coat, although some may become depigmented and acquire a whitish colour.

Diet: Their diet is varied and includes fish, crustaceans, and cephalopods. Females only fast for the first few days of their pups’ lives, before venturing out to sea in search of food. Pups are weaned at four months old.