epic tiger shark diving expeditions
shark senses ampullae of lorenzeni

Shark Senses – How Do Sharks Hunt Their Prey?

Perfectly evolved over 500 million years and surviving 5 mass extinction events, sharks are true super predators. So how do they do it? What’s senses come in to play as sharks hone in on their prey? Here’s a quick look at each of the shark senses, and how each help make them successful predators.

Shark Senses – Long Range

Hearing. A long range and highly developed sense, the auditory system of sharks can also give important information about potential prey. This will often occur well before the animal is in visual range. They are especially tuned in to low frequency sounds, the kind made by a wounded or struggling fish, and are able to detect them often from distances greater than a kilometer away!

The Sense of Smell. It’s true, sharks have a great sense of smell. You may have heard some of those interesting little factoids such as sharks being able to smell a drop of blood in an olympic sized swimming pool. Well, it’s not far off from the truth. Sharks sense of smell (olfaction) is remarkably effective and fine tuned to pick up the amino acids in proteins, such as blood. Studies have shown sharks to be able to detect 1 part per 20 million parts water! This is likely one of the first senses that clues sharks in to potential prey items at a distance.

Shark Senses – Mid Range

Vision. Contrary to some myths out there, sharks actually have good eyesight, as far as fish are concerned. They lack color vision and only see in black and white, but still possess the visual sensory equipment to produce focused images. Water conditions play a big role and low light or murky water will have a big impact on their visual acuity. Take a look at our blog focused on Shark Vision for more details.

The Lateral Line – Mechanosense. Sharks have evolved another sense that is quite foreign to humans. The lateral line system is a series of canals located throughout the sharks body with openings to the skin. It allows for water to enter and is very sensitive to picking up water movements. Because of this, sharks are able to tune in to the vibrations caused by wounded or struggling fish, again helping them to hone in on potential prey.

shark lateral line

Shark Lateral Line System – illustration by Chris Huh

Shark Senses – Close Range

Ampullae of Lorenzini – Electrosense. Another sense unfamiliar to us is electrosense, the shark’s ability to detect the weak electrical field given off by all living things. This highly tuned sense is thanks to countless small pores located throughout the sharks skin, mostly concentrated around the snout, and called the ampullae of Lorenzini. These gel filled pores help amplify these weak electrical signals allowing sharks to detect prey even if it’s completely hidden, such as in the sand. It’s effective at close range, typically within 1 meter or less.

shark senses ampullae of lorenzeni

Shark Electroreception – illustration by Chris Huh

Touch. Obviously a close range sense, sharks will often bump potential prey items before taking a bite to get a better sense of what they’re dealing with. Lacking hands, it’s common for sharks to investigate items in the water column by hitting with their snout or even “feeling” with their mouths. This is the reason for the often described bump and bite scenario, and also a reason that we let divers know they cannot let sharks bump into them, as it’s often followed by a test bite.

Taste. Like us, sharks have taste buds in their mouths, making it the final sense involved in determining if a shark has found it’s next meal, or made a mistake. We have no idea what tastes good to a shark, but given the frequency that shark-human interactions only end in a single bite, and our terrestrial nature, it seems we are certainly not on the top of the shark menu.

 

howard hall filming a bull shark

Bull Sharks – knows no bounds

Description

Bull shark, Carcharhinus leucas, from the CARCHARHINIDAE family. Depending on where you are in the world, you might also hear it referred to as a Ganges shark, Zambezi shark, ground shark, shovelnose, freshwater whaler, swan river whaler or slipway grey.

As its name suggests, a bull shark is large, stout and unpredictable. They are distinguished from other sharks by their stout appearance. Male bull sharks grow to an average size of 7 feet (2.5 m), whereas the females are bigger, with an average length of 11 feet (3.5 m). They weigh about 200 lb (90kg), 290lb (130 kg) respectively.

Bull sharks are wider and heavier than other requiem sharks of comparable length, and are grey on top and white below. The second dorsal fin is smaller than the first. The bull shark’s caudal fin is longer and lower than that of the larger sharks, and it has a small snout, as well as lacking an interdorsal ridge. This species reaches maturity at about 6 years and lives to be least 14 years.

Location

bull shark carcharhinus leucas

Range of the Bull Shark

They’ve been spotted as far north in the Atlantic as coastal Massachusetts and as far south as Brazil. In the Indian Ocean, you can find them from Africa and India to Vietnam and Australia. They tend to avoid the cold waters of the Pacific. They can be a common sight in big rivers. There have been reports of bull sharks as far as 1000 miles (1600km) down the Amazon. They were also sighted in the Mississippi. It’s one of only two species of shark that can live in freshwater — the other is the rare river shark.

The ability to be able to survive in both freshwater and saltwater also gives it a benefit that has been driven by evolution. Because the majority of sharks are only able to survive in saltwater, the bull shark has evolved to have their offspring in the fresh water where other sharks cannot enter. The fresh water acts as a protective area where the young are able to grow and mature without the threat of larger sharks preying on the younger bull sharks.

Diving with The Bull shark

Bull sharks like to dwell in shallow coastal waters (less than 100 feet in depth) , so you can be sure to encounter them more frequently, than say, an Oceanic whitetip. The fact that they are considered territorial animals assures that you are bound to catch one with your underwater camera. Bull sharks are a sight to behold and are a truly unforgettable experience for any scuba diving enthusiast.

shark diving with lemon sharks

Lemon Sharks: A Tiger Beach Bahamas Regular

Description

shark diving at tiger beach with lemon sharksLemon sharks, Negaprion brevirostris, gets their name because of its pale yellow brown coloring. It is also known as requin citron (France), tiburon galano (Spain), squalo limone (Italy), zitronenhai (Germany) cacao-limao (Brazil), requiem shark (UK).

Lemon sharks use their yellow color to successfully hide in their natural habitat. They can be found swimming along the sand at the bottom of the water, which protects them from predators and gives them an advantage over their prey.
The lemon shark is a large, stocky, blunt nosed shark with two dorsal fins of similar size. The first dorsal fin is low and positioned posterior to the pectoral fins, the second dorsal is of similar shape and size and positioned anterior to the origin of the ventral fin. The pelvic fin has weakly concave rear margins and the outer margin of the pectoral fin is slightly convex. The snout is round and shorter than the width of the mouth. There is no mid-dorsal ridge present on this species. Like most sharks, lemon sharks have very sharp teeth, but they are shaped differently. They are curved rather than all the way up and down. This allows them to easily catch slippery fish.

It commonly attains a length of 2.4 to 3.1 m (7.9 to 10.2 ft) and a weight of up to 90 kg (200 lb). Their life span is over 25 years.

Location

The lemon shark inhabits coastal inshore waters from New Jersey (US) to Southern Brazil, Gulf of Mexico and Caribbean in the northwestern Atlantic Ocean and along Senegal and the Ivory Coast of Africa in the eastern Atlantic. This species of shark often occupies the subtropical shallow waters of coral reefs, mangroves, enclosed bays, and river mouths, making them an ideal scuba diving attraction.

Diving with Lemon sharks

Since they are so frequent around the Bahamas, Lemon sharks have been extensively studied in recent years in the wild off Bimini. They are social animals and like to live and hunt in packs, so you can expect an interesting encounter when diving with this kind of shark. They present a minimal threat to divers and prefer to swim slowly, so one can hope to have a nice and rewarding experience when diving alongside one. Lemon sharks are a guaranteed encounter on any of our Tiger Beach shark diving expeditions, where you will also see Tiger Sharks!

lemon shark cleaning Tiger Beach Bahamas

tiger shark at tiger beach daniel botelhol

Tiger Sharks: Perfect Scavengers

Background

The tiger shark, Galeocerdo cuvier, is a member of the order Carcharhiniformes, characterized by the presence of a nictitating membrane over the eyes, two dorsal fins, an anal fin, and five gill slits. It is the largest member of the family of requiem sharks.

Characteristic Features

Tiger sharks at tiger beach bahamas

Distinct Tiger Shark Stripes. Image by Daniel Botelho

Known for the stripes that appear on their back, tiger sharks are a relatively large species of shark that live primarily in tropical and subtropical regions around the world. While the stripes do appear distinctly in younger tiger sharks, as the sharks grow and mature, the stripes actually begin to fade and become much less apparent on adults.

Tiger sharks are one of the largest shark species, just behind the more-famous Great White Shark. Born at only 20 – 30 inches long, they have been know to reach lengths of up to 16 feet (5 meters) as adults, with some larger specimens reported. Adult females tend to be larger than adult males. The tiger shark also has very unique teeth, easy to distinguish from any other shark species. Their upper and lower jaws are identical.

tiger shark anatomy
Illustration by Marc Dando. Check out www.wildnaturepress.com.

Location

Tiger sharks are not afraid swimming closer to coastal lines which make them a perfect species of shark to see, and one of the most popular, if you are looking for any type of Bahamas shark diving adventures.

In addition to being very common among warm coastal waters, another reason that the tiger shark is so popular during Bahamas shark diving expeditions is that the animal is extremely inquisitive and unafraid.
As a result, shark divers won’t have to worry about scaring away a tiger shark as easily as other species, like the great hammerhead, which can present a great opportunity to examine and photograph one of the ocean’s greatest predators. A tiger shark that was tagged in the Bahamas was noted to follow the Gulf Stream as far north as Cape Cod. They tend to remain in deep waters that line reefs, occasionally exploring more shallow water. Tiger sharks have been recorded at depths of 900 meters, or 3,000 feet!

Tiger sharks range and distribution

Tiger shark range and distribution. Image by The Emirr

Tiger sharks are excellent scavengers with amazing eyesight, even in comparison with other shark species, and are known to have an extremely keen sense of smell. Those skills make them particularly effective night time predators.

Diving with Tiger Sharks

Most of the tiger sharks you’ll encounter at Tiger Beach are well behaved, slow moving animals.  There’s no mistaking their large size and tremendous power, but it’s unusual to get such a display.  Divers can expect that the tiger sharks will swim right up to them and must pay close attention at all times.  There are often multiple animals and occasionally a dozen or so individuals at the boat.  SCUBA diving with these sharks means keeping your head on a swivel and taking notice of where each shark is at all times.  It’s easy to get focused on the sharks that are in front of you and forget to notice the ones behind you.

Want to Dive with Tiger Sharks?

Interested in diving with tiger sharks? Click here to learn more about our tiger shark diving expeditions at Tiger Beach.  Here you will also see Reef Sharks and Lemon Sharks, as well as occasional Nurse Sharks, Bull Sharks, and Great Hammerhead Sharks.

Additional Information

Looking for more fun facts? Check out this great PDF fact sheet put out by Shark Trust