![]() And this wasn’t an isolated incident-tagged whale sharks off the coasts of India have been recorded hitting 2200- to 3200-foot depths as well. One of the Wilson team’s specimens, for instance, spent at least 12 uninterrupted hours at a depth of 3215 feet. With that said, though, whale sharks occasionally travel much, much further down. According to their results, the sharks mostly avoid deep plunges-in fact, the surveyed animals spent over half of their time within 100 feet of the surface. Wilson studied the long-term movements of six different whale sharks near western Australia. WHALE SHARKS ARE LIABLE TO JOURNEY FAR BELOW THE SURFACE. For the record, scientists aren’t completely sure about the great white shark’s maximum lifespan either-though they’re now known to reach age 70 or more. Others speculate that whale sharks can live to be 100 or even 150 years old. According to some ichthyologists, the big fish probably die in their sixties. Most experts agree that whale sharks reach sexual maturity around age 30, but their total life expectancy is unknown-and estimates are all over the map. Conversely, their underbellies are relatively soft and vulnerable-so when approached by human divers, a whale shark will often turn its belly away from them. Whale sharks can toughen this skin still further by clenching the muscles that lie just beneath it. ![]() PARTS OF THEIR SKIN ARE INCREDIBLY TOUGH.Ĭovered in hard, tooth-like scales called denticles, the hide on a whale shark's back can be up to 4 inches thick. For example, huge schools visit exotic locales like the Galapagos Islands and Yucatan Peninsula every summer to gorge on plankton. Though scientists don’t fully understand their migration habits, we know that the fish tend to gather en masse in specific places at specific times. Within this range, they move around a lot: In three years, a single whale shark can travel 8000 miles or more. Generally, whale sharks-which are tropical and sub-tropical fish-are encountered from latitudes 30° N to 35° S. Here’s a look at this second method in action: 6. But when it sees a dense cluster of potential targets, the shark changes tactics: The animal creates suction by rapidly opening and closing its jaws, pulling dinner into its cavernous maw. This low-energy feeding technique allows the beast to passively swallow any food items that might be in its path. Sometimes, a whale shark will lazily swim with its mouth agape. Eventually, the meal is forced down our whale shark’s narrow throat and digested. Attached to the gills is a mesh-like network of long, cartilaginous bars known as “gill rakers.” These allow water to escape, but prevent even millimeter-sized victims from doing so. The sharks usually swallow their food whole. Despite their enormous size, whale sharks exclusively dine on very small life forms like plankton, krill, fish eggs, and small fish. WHALE SHARKS CAN FEED VIA SUCTION.Īll those teeth don't do very much, though. That means a whale shark has 3000 individual teeth, each one about the size of a match head. Most sharks have 20 to 30 rows of pearly whites, but whale sharks have more than 300 rows. By then, the creatures have-again, in theory-become big enough to scare away would-be attackers. Once the fish reach a certain size, scientists theorize that their growth rate slows down considerably. Another infant showed the astonishing growth rate of 18 inches per year over 630 days.īut, like human babies, young whale sharks don’t keep growing at the same speed forever. These youngsters have every incentive to get big quick-which is exactly what they do.Ĭonsider this: In just three years and 68 days, one newborn whale shark at Japan’s Oita Ecological Aquarium went from weighing 1.7 to 333.4 pounds. Juveniles, on the other hand, are easy pickings for predators like blue sharks and marlins. ![]() Thirty or 40-foot adult whale sharks have few natural enemies. Afterward, the little fish exit her womb fully-formed. In other words, whale sharks-like certain snakes-hatch from eggs that are stored inside their mother’s body. This discovery confirmed that the species is ovoviviparous. An autopsy revealed that her uteri (all sharks have two) contained around 300 unborn embryos. Then, in 1995, a pregnant female was fatally harpooned near Taiwan. ![]() For years, there was much debate over how baby whale sharks come into the world.
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