mysteries under the sea

Lion’s Mane Jellyfish

Photograph by Paul Nicklen, National Geographic

             The world’s largest creatures reside in the ocean, and its depths are home to unusual species whose surprising proportions are unknown on land.

Here, an underwater view captures the billowing tentacles of a lion’s mane jellyfish. The most potent species of jellyfish, the lion’s mane can reach a diameter of 6.6 feet (2 meters) with tentacles topping 49 feet (15 meters).

Red Sea Urchins, British Columbia

Photograph by Paul Nicklen, National Geographic

 

 

              Visually arresting, hazardous to swimmers, and—to some cultures—delicious, sea urchins are also revealing new information to the scientists who study them.

Here, red sea urchins carpet a kelp forest off British Columbia. The marine invertebrates are important links in the marine food chain. Fish pick at the urchins, which feed on bits of algae.

Banded Sea Krait

Photograph by David Fleetham/Visuals Unlimited, Inc./Getty Images

              The banded sea krait’s lethal venom packs a punch ten times more toxic than a rattlesnake’s, but fortunately these serpents are so meek that human bites are rare. Kraits cruise the shallow, tropical waters of coral reefs and mangrove swamps. But, alone among the sea snakes, they are amphibious and able to spend up to ten days at a time on land. Sea kraits hit the beach to digest their food (mostly eels and fish), mate, and lay eggs.

Caribbean Reef Squid

Photograph by Brian J. Skerry, National Geographic

            More than 280 species of squid live in the oceans worldwide. Many are masters of transformation, able to change their skin color and pattern in seconds to stalk prey, escape enemies, attract mates, stand up to rivals, and communicate with one another. Here, a Caribbean reef squid defends its claim to a nearby female by flashing an aggressive zebra pattern, just one of about three dozen designs in its wardrobe

            Clouds of longfin inshore squid head to the shallow, green waters of Cape Cod, Massachusetts, each May to spawn. Squid move using jet propulsion, contracting their bodies and forcing water through a moveable funnel beneath their eyes