shark species week #5
Scalloped hammerhead shark close-up, Dirty Rock, Cocos Island, Costa Rica
Canon EOS 350D + Canon EF-S 10-22mm, single strobe Sea&Sea YS-110
this image is 5% cropped from right and top, very minor contrast adjustment in Photoshop, very minor garbage cleanup in Photoshop
Location on Google Maps
Wikipedia reference
Moving further up shark hierarchy - or even not really up, more like sideways. Scalloped hammerhead, one of the hammerhead sharks species is like most advanced, evolution-wise very new shark, top model :-) Definitely one of my favorites ! It has very unusual shape of the head to enhance vision and also to improve electric field sensitivity by having more receptors distributed over wider area. It is also believed that head is used for two more purposes - to push pray towards bottom while hunting and to stabilize body during turning maneuvers. Scalloped hammerheads are known to congregate into huge schools - for the reasons fully unknown to the science. This magnificent animal is full of mysteries and questions which still needed to be answered.
I saw hammerhead shark first time in my life in Cocos island in 2007, one of the greatest shark sanctuaries in the world. It was followed by great sightings during trip to Galapagos in 2008. Interestingly enough that hammerheads are often seen in various places in Japan where I lived for long time, like Izu peninsula, but I never had chance to see them where. Population of hammerheads is dropping dramatically around the world due to the shark fin trade, and this shark unlike previous species from my shark week has true "endangered" status - it is said that in Cocos population dropped as much as 80% or more during last 15 years.
Scalloped hammerhead can grow up to 4 meters - they are quite big, but during day time don't present much danger to the divers.
In regard to the hammerhead sharks, I heard today some preliminary sensational news which can turn around whole thing about "who is the biggest shark in the sea" question. I'm waiting for more info to follow - this is going to be very interesting if it is true ! :-)