Whale Shark Sightings Always Cause A Buzz Around Phuket But What Facts have We Got
Well we know whale sharks are big and spotty but not a great deal else to be honest. It’s a challenging animal for scientists to study. They’re trying and we’re slowly gaining an insight into the biggest fish on the planets life. There is a way that you can help which we’ll touch on later.
Just How Big Do Whale Sharks Grow?
There’s much debate about the size to which they can grow. 18m is a common figure that’s mentioned but the largest verified measurement is around 12m. In Thailand we rarely see whale sharks larger than 6m but this seems to be a global trend. Apart from the Galapagos Islands, large whale sharks are becoming increasingly rare. The most studied group of whale sharks (Ningaloo Reef, Australia) now average around 6m, at this size whale sharks are not thought to be sexually mature – a very worrying trend.
Why The Spots?
Most likely to reflect and disperse light and aid camouflage. Along with this, the whale sharks skin on its back is thicker and tougher than any other animal. The skin on its back can be up to 6 inches thick! Overlapping dermal denticals cover the outer layer and act like a suit of armour.
Where Do They Go?
Whale sharks live in warm – temperate tropical seas all around the globe. Preferring temperatures of 22c or above. There’s thought to be two large populations, one in the Atlantic and one in the Indo Pacific. They travel huge distances within their ranges. One tagged female recently logged a journey of 7,800km and was still going when the tag dropped off. Where the large females go to give birth is the holy grail of whale shark research and probably the key to keeping the species from extinction
Whale Sharks In Phuket
We can’t with all honestly say that we’re inundated with whale shark sightings. However they’re regular enough visitors to get a mention in dive briefs. Of the local dive sites – Shark Point probably gets the most sightings and if you venture a little further afield then Richelieu Rock gives you a chance but probably Hin Daeng and Hin Muang gives you the best chance of an encounter with these magnificent animals.
The Whale Sharks Entourage
Whale sharks are very often accompanied by large numbers of remora, slender suckerfish and large cobia. Much like the entourage that accompanies celebrities they’re a fairly useless bunch to the ‘star’ and basically freeload a ride off the shirt tails of the main attraction. The accompaniment of spongers get a certain degree of protection from their 20 ton friend and feed from its left overs and pooh but give little if anything in return.
Whale Shark And it’s Entourage
Dining Preferences
Whale sharks are plankton feeders but will also feed on fish eggs, krill, small fish and squid. They mostly swim around with there mouths open but they can also use suction to engulf vast quantities of water and filter out the good stuff with a unique sieve like structure that is thought to be modified gill rakers. They have an uncanny ability to appear just at the right time for mass spawning events of coral and fish and gorge themselves on the rich fair.
Reproduction
Pretty much a blank here. Whale sharks mating behaviour has never been witnessed*. Most of the large gatherings around the globe seem to be immature animals and 70% male so it’s unlikely that any naughtiness is going on here. We do know that they give birth to live young (ovoviviparous) after a dead female was dissected and found to have 300 pups inside.
*Update: Whale shark mating was recently witnessed and filmed at Ningaloo Reef
The pups are born 40 – 60cm long and will have a long wait before they can breed themselves. It’s thought that they can breed only when they reach about 30 years of age. Whale sharks are estimated to live as long as 100 years.
Dangerous?
Not at all, unless somebody dropped one on you, that would probably leave a few bruises. Even though they do have 300 rows of tiny teeth, curiously they aren’t used for feeding in any way. Getting to close could get you whacked by the tail but that’s your own fault and you’ll get no sympathy.
What Can You Do?
You’ve probably noticed that there’s a lot of: possibly, it’s thought, suggested etc in this blog which shows regardless of a lot of people’s hard work we still know very little about these magnificent animals. Studying a creature with such a long life span that travels so far and dives so deep is an immensely difficult task.
You can report your sightings on the Wildbook for whale sharks website. Cameras seem to be as important as regulators to divers nowadays and taking a photo can help identify individual animals and help understand their movements. The photo has to be of a specific area of the animal which Wildbook clearly outline on their website. I know we all get a little excited when we see one but try to calm down and get a shot which can help.
So catch your breath start clicking the camera and help save an animal that simply must always be in our oceans.
By Justin Hartrey
Posted in Rare & Peculiar Critters on .
