A giant of the ocean, the gray whale is mottled dark to light grey in colour and is encrusted with patches of barnacles and whale lice (4). The species lacks a dorsal fin and instead has a series of bumps along a dorsal ridge on the final third of the back (2). There are two deep grooves on the throat, which allow the mouth to expand when feeding, and the baleen, which is used to filter food, is cream-white in colour. When surfacing, the 'blow' produced is distinctly bushy, short and forked, or 'heart-shaped', as it comes from two blowholes (2) (5). Females tend to be larger than males but otherwise the two sexes are similar in appearance (5). Whalers referred to gray whales as 'devilfish', due to the ferocity of mothers when separated from their calves (4) (5).