7 Facts About Hammerhead Sharks
Douglas David Seifert had the pleasure of diving with several hammerhead shark species throughout his career and has always been fascinated with their physiology and behaviour. Here's 7 amazing facts
Download our Free June 2015 issue for more of Douglas' stunning images and the answers to a few puzzling questions (Why do they school?).
1 There are nine species in the family of hammerhead sharks
- Bonnethead shark (Spyrna tiburo tiburo)
- Carolina hammerhead (Sphyrna gilberti)
- Golden hammerhead (Spyrna tudes)
- Great hammerhead (Spyrna mokarran)
- Scoophead shark (Spyrna media)
- Scalloped bonnethead (Spyrna corona)
- Scalloped hammerhead (Spyrna lewini)
- Smooth hammerhead (Sphyrna zygaena)
- Winghead shark (Spyrna blochil)
2 THE USE OF THE HAMMER
In the case of the great hammerhead, the hammer has been observed as being utilised for trapping and holding prey against the bottom while scalloped hammerheads are observed continuously swinging their heads to and fro in an arc as they swim, analysing sensory information between their widespread receptors.
3 The inner compass
Tracking experiments indicate that hammerheads may be able to follow ‘highways’ in the ocean using the magnetic field of the sea floor. By comparing and analysing the differential between strength and weakness of these magnetic fields, the hammerheads can follow a consistent route, routinely tracing the paths of ridges and valleys which radiate outward from sea mounts and pinnacles, to and from deep water feeding grounds and their sea mount resting stops.
4 A Shiver of SharkS
Most people are familiar with ‘a school of fish’, but when it comes to the subject of sharks, the proper plurality is defined as ‘a shiver of sharks’
Great hammerhead shark females reproduce bi-annually, unlike the rest of hammerhead species, which reproduce annually and the number of pups per litter can reach as high as 56.
Great hammerheads are one of the largest of predatory sharks, surpassed in size only by great white sharks and tiger sharks, with some extraordinary individuals possibly reaching 5.5m in length, however the largest female of this shark species accurately measured and weighed was 4.3m and 572kg (much of that weight in her unborn pups).
7 Where to see theM
Currently, one of the most reliable places to encounter great hammerhead sharks is The Bahamas.