Marine Life: The 2010 Sea Otter & Harbour Porpoise, a souvenir sheet of 2 stamps from Canada.

Canada Post is teaming up with Sweden, another country whose coastal waters abound with marine life, for a 2010 souvenir sheet of two commemorative stamps featuring the fun-loving sea otter (Enhydra lutris) and the timid harbour porpoise (Phocœna phocœna).

Though their trademark long whiskers have earned them the nickname, “old men of the sea,” sea otters (Enhydra lutris), known for their aquatic acrobatics and whimsical behaviour, seem much more like youngsters at play. The largest animal of the weasel (Mustelidae) family, sea otters typically reach about 4 feet in height, weighing in at 45 to 100 pounds. Except for the pads of their paws and the tips of their noses, they are completely covered in thick, rich fur—the thickest in the animal kingdom, in fact. Without the insulating blubber possessed by nearly all other marine mammals, this fur is essential for their survival in the often-frigid temperatures of the world’s oceans.

The shy harbour porpoise (Phocoena phocoena) is among the smallest of whales, rarely exceeding 1.5 metres or 130 pounds. Its mottled greenish-white sides fade to almost white along the belly, helping it blend well in a marine environment. Harbour porpoises are found primarily over continental shelves in Canada in two populations: the Pacific and the Northwest Atlantic. They’re also known to spend time in bays and harbours during the summer.

Both commemorative stamps show the otter and porpoise in a setting of waves and bubbles. On the souvenir sheet, Canada Post introduced elliptical perforations, and Sweden has re-created the maple leaf perforation using new techniques.