Great White Shark

Two Tons of Muscle, Seven Decades of Growing

A great white shark can weigh up to 4,500 pounds and grow to 21 feet long, though it starts life as a pup only about 4 feet long, according to NOAA Fisheries. A 2015 study that counted growth bands in shark vertebrae, checked against radiocarbon left over from nuclear bomb testing, validated age estimates up to 44 years and concluded that white sharks grow more slowly and live far longer than researchers had thought. NOAA now lists the species’ lifespan at 70 years or more.

A Diet That Ends in Seals, Sharks, or a Dead Whale

Adult great whites eat seals, sea lions, elephant seals and dolphins, plus other sharks and mobulid rays, and they scavenge whale carcasses. They range through temperate and subtropical waters worldwide, cruising anywhere from the surf line to the open ocean and diving from the surface to more than 1,300 meters down. Large, erect, triangular, serrated teeth do the cutting once the shark closes the distance.

An Ambush Timed by Sunlight

Off Seal Island in South Africa, researchers logged 2,088 natural attacks by white sharks on Cape fur seals between 1997 and 2003. Most strikes lasted under a minute and came down to a single breach aimed at a young seal swimming alone near the surface. Timing decided almost everything: attacks succeeded 55 percent of the time within an hour of sunrise, then failed more often as the sky brightened. Once their success rate fell to around 40 percent, the sharks stopped hunting seals for the day.

Electric Radar and a Furnace Under the Skin

A great white’s snout is covered in pores called the ampullae of Lorenzini. They can detect electrical signals as faint as 0.005 microvolts, like the ones a beating heart or working gills give off.

A fish that runs its own heater White sharks are the largest fish known to practice regional endothermy, keeping key parts of their bodies warmer than the surrounding ocean instead of matching the water’s temperature the way almost every other fish does.