Leptonychotes – Weddell seal

One of the most remarkable marine mammals on Earth, perfectly adapted to life in one of the harshest environments—the frozen seas of Antarctica. Named after the British sealing captain James Weddell, who explored the Southern Ocean in the 1820s, this seal is famous not only for its resilience but also for its extraordinary ability to survive beneath the Antarctic ice.

Weddell seals are large, sturdy animals, with females slightly larger than males, making them among the heaviest true seals. Their fur is mottled gray and silver, often patterned with lighter spots, which provides camouflage against the ice and snow. They have large, dark, soulful eyes—perfect for spotting prey in the dim underwater world—and their small heads with short snouts make them look almost gentle, belying their tough lifestyle.

What makes the Weddell seal truly extraordinary is its ice-diving ability. Unlike many seals that live near open water, Weddells thrive in areas covered with solid sea ice. They use their strong teeth to gnaw breathing holes through the ice, maintaining access to the ocean even when the surface is frozen solid. This behavior allows them to live farther south than any other mammal. They are also champion divers: a Weddell seal can hold its breath for over 80 minutes and dive to depths of more than 600 meters (2,000 feet) in search of fish, squid, and other prey. Their blood carries high amounts of oxygen, and they can slow their heart rate dramatically to conserve energy while underwater.

Weddell seals are known as the “singers of the south”, producing an incredible variety of underwater sounds, from eerie whistles and trills to metallic “boings” and electronic-sounding pulses—vocalizations that travel long distances through the ice. Their teeth wear down from constant ice-gnawing, and older seals sometimes starve when they can no longer keep breathing holes open.