Behaviours for survival
Whale Shark
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Learned behaviour: |
ReproductionMale whale sharks have the ability to fertilise an entire litter, and this suggests that female whale sharks utilise a form of sperm storage to fertilize the eggs in successive phases. This behaviour also suggests that whale sharks rarely mate with a single individual, so breeding areas with a large number of adults do not exist for this species. Tagged female whale sharks have also been observed to exhibit natal philopatry (the tendency of an organism to stay in, or return to, its home area).
In July 1995, a female whale shark was examined off the East Coast of Taiwan to contain 50 empty, thin-shelled egg cases and 301 fetal pups (all well-formed). Upon the finding of this specimen, it is too early to draw conclusions. Although, if this shark is typical of her species, it means that whale sharks give birth to large litters of well-formed pups, meaning they are ovoviviparous, and this could be because there is a high juvenile mortality rate. FeedingThe whale shark possesses practically no snout and very broad jaws with numerous tiny teeth, and have a variety of feeding techniques, including suction and active surface ram-feeding. In ram filer feeding, the fish, in this instance the whale shark, swims forward with its mouth partially or fully open at constant speed, straining prey particles from the water by forward propulsion. This form of feeding is also called 'passive feeding', due to the small amount of pumping of the gills, and it usually occurs when prey is present at low density. On the other hand, when a whale shark opens its mouth forcefully, sucking or gulping in prey, this technique is called suction feeding.
Whale sharks tend to "assume a vertical feeding posture with it's mouth uppermost near the surface and actively 'pumps' its body up-and-down in the water". This 'pumping cycle' lasts between 15 to 20 seconds, and the whale shark repeats this process, pausing at the waters' surface each cycle to allow food-bearing water to flow into it's mouth, straining through the spongy gill plates. |
Operant conditioningWhale sharks have demonstrated, in captivity, changes in behaviour when their keepers appear with food, swimming in tight circles near the feeding area. They are also known to swim around local fishing boat nets looking for small fish, and have been sighted accepting handouts of fish from fishermen.
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