Emotional anguish and whale shark encounters
Posted By Vladimir Soto on 6 December 2006
Whale sharks are filter feeders, meaning they swim slowly (that's in reference to other sharks, of course, since even trying to keep up to them with fins and snorkel would definitely count as a rigorous cardio workout) close to the surface with their huge mouths open, feeding on phytoplankton, tiny plant life or zooplankton, tiny sea criters, squid and small fish. Although they do have about 300 rows of teeth, these are very small. They never chop up their food with them, they filter feed with their gill rakers, or very small hooks found on their gill arches, which act like sponge-like filters. That said they have been known to position themselves vertically, head up through the middle of plankton agglomerations or schooling fish. At times small fish might enter their mouths thinking they are entering a cave they can hide in while being chased by predators like tuna. Once the larger fish enters the shark's mouth this can dart upwards through the surface of the water, allowing gravity to throw both fish down into it's stomach. Not a bad strategy for an animal with an apparently insignificant brain, huh?
They are also known to be able to pump water into their mouths and filtering system by moving their head from side to side while opening and closing the mouth up to 28 times per minute, creating a suction that can draw prey into them. Along their sides, starting from around their first dorsal fin, they have lateral ridges, at the valleys of which they have a formation of nerves that can 'feel' the water pressure, thus sensing the size and distance of a swimming colleague, prey or for that matter an out of shape struggling snorkeler.
Another peculiarity is apparently what they do when they feel they've consumed the equivalent of 2 week old sushi, they can force their stomachs out of their mouth to expel whatever it is they feel is making them gag.
Very little is known about their courtship and mating habits, due to the incredibly large distances whale sharks travel. However, not long ago heated scientific debate was settled as to how the young are born. A female shark also caught in Taiwan was discovered to have up to 300 pups inside its twin uterus, proving that the pups develop inside egg cases but eventually are given birth as live pups. Apparently these can be up to 2 feet (60cms) when they are born. Young adults don't seem to reach mating age until their late 20's, having a life expectancy of over one hundred years.
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