Some sea sponges can live for centuries, and are indeed animals. PHOTOGRAPH BY JAD DAVENPORT, NATIONAL GEOGRAPHIC CREATIVE

That’s a question National Geographic reader Mohamed Larbi Bahou asked the columnists of “Weird Animal Question of the Week,” and a question we hadn’t asked ourselves. Liz Langley answers Mohamed’s question – thanks to both of them for these interesting facts:

Some days it feels like it might be me.

Kidding aside, humans these days live pretty long lives: The average global life expectancy of someone born in 2015 is 71.4 years.

That’s not bad compared with some adult female mayflies, which live for under five minutes—just long enough to mate and lay eggs. Talk about speed dating.

We did some digging and found some animals who are really getting the use out of their senior discount cards.

The Old Clam and the Sea

The sea harbors many a Methuselah.

Take sponges, for example. “People often forget sponges are animals”—and some of them very long-lived animals at that, Marah J. Hardt, author of Sex in the Sea: Our Intimate Connection With Sex-Changing Fish, Romantic Lobsters, Kinky Squid, and Other Salty Erotica of the Deep, says via email.

Estimates of sponge longevity vary quite a bit, but are often in the thousands of years. One study in the journal Aging Research Reviews notes a deep-sea sponge from the species Monorhaphis chuni lived to be 11,000 years old.

Ming, a quahog clam, died at the age of 507 when researchers tried to dredge the bivalve up from Icelandic waters. The quahog’s life-span is usually about 225 years. (Also see “405-Year-Old Clam Called Longest-Lived Animal.”)

Some deep-sea fish, like the orange roughy, live to be 175 years old, according to the book Sexuality in Fishes.

As far as mammals go, bowhead whales seem to have the most candles on their cake—over 200. It makes sense, since the marine mammals live in chilly waters, says Don Moore, director of the Oregon Zoo in Portland. (Related: “Six of the World’s Longest Lived Mammal Species.”)

A cold environment causes a low body temperature, which in turn means slow metabolism—and thus less damage to tissues, Moore says.

Incidentally, according to the National Ocean and Atmospheric Administration, the bowhead also has the largest mouth of any animal. No comment.

Long-Lived Landlubbers

Currently the world’s oldest known land animal is Jonathan, an 183-year-old Aldabra giant tortoise that lives on the grounds of the governor’s mansion in St. Helena, an island off West Africa. (Related: “Healthy Diet Helps 183-Year-Old Tortoise Feel Young Again.”)