At sunrise, if the conditions are utterly perfect - deep water, plenty of cleaner fish and nutrient-rich currents - you might just spot a thresher shark. For many scuba divers, encountering these shy creatures is a bucket list experience - and for good reason. Seeing a thresher shark's long, wispy tail sashay into view, along with its cartoonish big eyes, is one of the ocean's most enticing sights. However, a penchant for the deep means these elusive predators are hard to come by, although we have a few hotspots up our sleeve. If you've yet to see these long-tailed beauties, up your chances with our top ten thresher shark facts.
1. Three's Company
Within the thresher shark family (Alopiidae), there are three recognized species: the common thresher, the bigeye thresher and the pelagic thresher. While each species shares the same iconic long tail, they have slight variations in size and habitat. Take the common thresher shark, which is the largest of the three species and can grow up to 19 feet. On the flip side, pelagic threshers only reach three feet, while bigeye threshers are typically 13 feet. As for habitat, you'll only find pelagic threshers in the Indian and Pacific Oceans, while common and bigeye threshers roam the vast expanse of the world's oceans.
2. Deadly Tail Slap
The thresher sharks' most distinguishable feature, its whip-like tail, is mainly used for hunting. Also known as caudal fins, these tails measure half the length of their body and are used to stun and herd prey. With a flick of their tails, thresher sharks can create shock waves that immobilize schools of fish - their favourite dish - making them easier to catch.
3. Deep Ocean Dwellers
While thresher sharks are primarily pelagic, they breed in coastal waters. Juvenile thresher sharks will stick to these shallower, safer waters until they reach maturity, after which they will migrate to the deeper open ocean. Threshers will spend most of their lives at around 550 metres, but have been recorded reaching depths of 1,500 metres, making them one of the ocean's deepest dwellers.
4. Speed Demons
The thresher shark reigns as one of the fastest predators in the ocean, reaching impressive speeds of up to 22 miles per hour. Comparatively, great white sharks reach 15 mph, while nurse sharks cruise at a leisurely two mph. Their competitive edge comes from their extra-long trail and torpedo-shaped body, which helps them dart through the water.
5. Flying Acrobats
One of the most spectacular behaviours of thresher sharks is their ability to breach the water's surface. They use their powerful tails to propel themselves out of the water, reaching heights of up to three metres. The reason behind this behaviour is still not entirely understood, but it's believed to be related to communication, parasite removal or just for fun.
6. Warm-Blooded Adaptation
Unlike most other sharks, thresher sharks have a unique adaptation called regional endothermy, allowing them to maintain their body temperature above that of the surrounding water in certain areas. This allows them to venture into cooler waters and chase prey at varying depths.
7. Mysterious Migrations
Thresher sharks have a mysterious migratory pattern that continues to puzzle researchers. While some individuals may be more sedentary, others embark on incredible journeys across vast oceanic distances. The reasons behind these migrations and their destination points are still not fully understood.
8. Conservation Concerns
Like many other shark species, thresher sharks face significant conservation challenges due to overfishing and bycatch. Their slow reproductive rates make them particularly vulnerable, underscoring the need for responsible fishing practices and marine conservation efforts.
9. Diving with Thresher Sharks: Monad Shoal, Cebu, Philippines
Monad Shoal is an underwater island found off Malapascua Island in Cebu, Philippines. This site is also the only place in the world where pelagic thresher sharks can be seen every day. Also known as Shark Point, Monad Shoals acts as a cleaning station and features a sunken coral plateau 20 metres deep with a 200-metre drop-off. Bonus thresher shark fact: this is a dawn dive at around 6am, so fuel up on coffee! For the best thresher shark interactions, aim to dive Monad Shoal over a few days.
10. Diving with Thresher Sharks: The Plateau, Fuvahmulah Atoll, Maldives
Located in the deep south of the Maldives, few venture to the Fuvahmulah Atoll. However, those who make the voyage south will be rewarded with one of the sharkiest dives in the Maldives. The Plateau, on the south side of Fuvahmulah island, acts as a pelagic pit stop and cleaning station in the open ocean, attracting a whopping seven species of shark, including threshers. The site reaches a maximum depth of 30 metres, which, coupled with strong currents, means it's only suited to advanced divers.
