8 Most sharks have the ability to detect electromagnetic fields given off by other animals in the water. This sense is so strong in the Great white sharks that they can even hear heartbeats if their prey is nearby.

Most sharks have the ampulla of Lorenzini, or simply put, sensory organs called electroreceptors. These detect electric fields in water which is given off by animals’ activity in the water. Every living being produces an electric field generated by their muscles contracting, and this is perceived by sharks. The great whites have an even more heightened sense, which enables them to discern variations of “half a billionth of a volt!” This means that they are immediately able to trace other living beings nearby, even if they are not moving, by sensing their heartbeats. This makes them excellent predators. (source)

9 A study has shown that sharks are known to have a rush hour. Shark traffic showed an increase around Palmyra Atoll between seven and eight in the evening.

The University of California used an acoustic camera, which is a dual-frequency identification sonar, to study sharks. They discovered, that like humans, sharks too had a rush hour around Palmyra Atoll near Hawaii. They observed animals using a World War II dredged channel as a kind of road which led to and from the lagoon. They recorded almost 1200 sharks in a month, coming and going at almost the same time every day. The number significantly increased in the evening between seven and eight. This could be because they are likely to hunt early in the evening. (source)

10 The short fin mako shark is the fastest shark species in the world and is known to be able to leap up to 30 feet or more, in the air.

The Mako shark is known to have remarkable speed, clocking a record of 25mph with short bursts ranging up to 46mph. This enables it to jump up to 30 feet in the air, with several instances of it jumping onto boats as well. Just this year, in July, a mako shark jumped onboard a fishing boat near Long Island, giving the crew a massive scare. In 2013 close to New Jersey, a 300-pound, eight and a half foot long, shark back flipped onto a boat after being hooked. (1,2)

11 People are known to have shown symptoms of extreme drunkenness after eating the untreated meat of a Greenland shark.

Hákarl is the national dish of Iceland, prepared with fermented shark meat which is hung to dry for almost five months. Holly Shiels, a professor of Biology, Medicine and Health at Manchester University says that if eaten untreated, it makes one “shark drunk” due to the toxins, making you dizzy and fall down as well.  The Greenland sharks have a higher content of urea and trimethylamine oxide (TMAO) as compared to other sharks in their bodies. This TMAO gets converted to a poisonous compound by the human body, which is why humans get sick if they eat untreated Greenland shark meat. (source)

12 A great white shark’s bite is not very strong as compared to other mammals like lions or tigers.

According to research, sharks don’t have a strong bite in correlation to their big jaws and sharp teeth. The lead researcher of the study, Dr Daniel Huber from University of Tampa in Florida, said that when compared to other mammals, these sharks have relatively weaker bites. They are able to get prey solely because of their speed, big heads, wide jaws and sharp teeth. The research team studied ten different species of sharks before reaching this conclusion.(source)

13 Sharks have been found living in an active underwater volcano in the South Pacific.

A report in 2015 detailed the studies of a group of scientists who discovered hammerhead sharks, silky sharks and the elusive Pacific sleeper shark, living in Kavachi. Kavachi is one of the most active underwater volcanoes near Vangunu in Solomon Islands, just 60 feet below the surface. What’s incredible is that is that the volcano has hot, acidic water all around it. The team sent down submersible robots with cameras which recorded these sharks living in the volcano. One of the team members, Brennan Phillips, stated that nobody knows how they survive in such inhospitable conditions or whether they get an early warning if the volcano is about to erupt. Kavachi has erupted a number of times in the recent past, the latest one being in 2014. (1,2)

14 There are sharks living in Ganga and Brahmaputra rivers in India.

They are critically endangered species, as per the International Union for Conservation of Nature. Their population has drastically reduced due to hunting for its fin and jaws. Interestingly, they do not need salt water to survive and do quite well in freshwater of the rivers. They have very small eyes and are thought to be poor sighted, probably because of the prevalence of murky water in these rivers. They are mostly found in the rivers Ganga, Brahmaputra and also in Hooghly and Mahanadi. However, sightings are extremely rare and a lot about them remains a mystery to us. (1,2)

15 A shark may be held in trance for up to 15 minutes if it is flipped onto its back.

Tonic immobility in sharks happens when it is flipped onto its back, and enters a state or trance or hypnosis. When this happens, their muscles and respiratory processes relax, their dorsal fins line up straighter and within 60 seconds and they are rendered immobile. Scientists believe that it could relate to mating behavior of sharks since females tend to suffer injuries at the hands of the males while mating. This phenomenon has been seen in whitetip reef sharks, blacktip reef sharks, lemon sharks, sandbar sharks, silky sharks and tiger sharks.

This is a very handy maneuver to know if you want to subdue a shark, and is typically used by researchers to avoid being attacked. In 1997, near Farallon Islands, a female Orca held a white shark upside down, essentially suffocating it by inducing tonic immobility, and then ate it. (1,2)