There are two stocks of hooded seals; one in the north west Atlantic and one in the Greenland Sea. They breed in 4 main areas; the Gulf of Saint Lawrence; the east of Newfoundland; in the Davis Strait between Greenland and north Canada; and on the ice near Jan Mayen island. The current world population is 500,000-700,000.

These silvery-grey seals have scattered dark spots. Mature males have an inflatable "hood" on top of the head and can also inflate their nasal septum through the nostrils to form a red balloon-like bladder. They were often called bladder seals by the Peterhead whalers.

Hooded seals eat deepwater fish, such as halibut, and squid.

Sexual maturity is reached at 3-5 years and live for 30-40 years. Rather loose aggregations of females give birth to single pups on heavy drifting pack ice in the second half of March. They have the shortest lactation period of any mammal. The young weigh 20 kg at birth and are weaned after just 4 days, when they weigh 40 kg!

National Oceanic and Atmospheric Administration Hooded seals

The drawing comes from NOAA's National Marine Fisheries Historical Image Collection - Over 532 etchings from the 1880s illustrating the various species of marine mammals, fish, and shellfish.