I was snorkeling off the Pacific Coast of Mexico with my friend and former dive instructor, Ceci, when I saw what looked like a spiny tetherball with a beak spiraling from the depths towards the surface. I lifted my mask and Ceci lifted hers, preempting my question.
“It’s a blowfish,” she said, matter-of-factly. Then, “All fish are weird.”
To wit: the whale shark. Not a whale at all, and only technically a shark (with a cartilaginous skeleton, gill slits, and pectoral fins it belongs to the shark family of fish), the whale shark has an enormous mouth with up to 350 rows of tiny teeth and 10 filter pads. Like baleen whales, they’re filter-feeders and eat by straining algae, plankton, and krill from the seawater, but their name more likely derives from the fact that at sizes of up to 40 feet long and 47,000 pounds, they are the largest fish on the planet, and can live for up to 80 years. Weird, right?
Whale sharks live in all tropical and warm temperate seas, so the regions where you can swim with them — they’re known to be gentle with divers — are numerous. Whale shark numbers, however, are dwindling; the animal is on the endangered species list.
The migration patterns of whale sharks aren’t fully understood, but there are ways to increase your chances of a sighting. Where you catch up with the whale sharks will depend on the time of year and the region you’re in.