When most people think of sharks, they think of species like the great white shark, tiger shark, and bull shark. These are known as requiem sharks and have that classic shark appearance. However, there a numerous species of shark that look very different from requiem sharks including the nurse shark (Ginglymostoma cirratum). These are very common sharks in the Caribbean and often encountered by new divers.
The head is broad with tiny eyes and has two barbels (whisker-like appendages) that are used in the search of food. Their teeth are small and designed for crushing as part of their diet includes eating shrimp, crab, and lobster. They are nocturnal and during the day they are often seen laying under ledges but are also seen in the open on the sand.
They are a fairly large shark and can reach over 3 meters or about 10 feet although most are much smaller. They can tip the scales between 90 to 115 kg (200-250 pounds). The gestation period for nurse sharks is about 6 months and generally, they have between 20-30 pups.
Although many divers see them as harmless, their mouth can produce a tremendous suction and could easily suck in fingers or a hand which they generally will not let go of. Therefore, like all sharks, they must never be touched and need to be respected.
Although we love to photograph all sharks, our favorite is the great hammerhead (Sphyrna mokarran). Generally, it is a cautious shark and will keep its distance from scuba divers. There are 9 species of hammerhead sharks worldwide but the great hammerhead is the largest. An average adult reaches lengths of about 3.6 to 4.3 meters (12-14 feet) but can reach 6 meters (20 feet) and exceed 550kg (1,200 pounds).
Great hammerheads are newer sharks on the evolutionary scale and have developed some unusual characteristics. The unique feature of this shark is obviously the head. The “hammer” which is called a cephalofoil is full of electrical sensors. These pores called ampullae of Lorenzini aid in hunting as these sensors pick up electrical signals given off by all living creatures including humans.
As you view these photographs notice how different the shark can look depending on the angle of the photograph. On a larger shark, the cephalofoil is about a meter (3 feet) in length and the eyes are at the ends which gives it a large range of vision.
The diet of this shark is diverse. They will feed on a variety of fishes including tarpons, porcupine fish and even other sharks. As well, lobster, squid, and octopus form part of their diet. However, their favorite food is rays. Stingrays bury themselves in the sand and the great hammerhead uses its cephalofoil with its electrical sensors to detect their location.
In South Africa we were supposed to see tiger sharks but they eluded us. In Mozambique we were supposed to see tiger sharks but once again we didn’t see any. Finding a specific shark species around the world is hardly guaranteed as these are wild animals that swim the oceans. However, we were told that if you want to see tiger sharks then you need to go to the world famous “Tiger Beach” to have the highest probability of seeing them. So here we are and finally we have seen tiger sharks!
Tiger sharks are big sharks. They are generally between 10-14 feet in length and weigh between 850- 1400 pounds. We encountered 8 different tiger sharks and two were in the 14 foot range. Being a few feet from them makes you realize just how big they are and how insignificant you are. Truly amazing creatures and a privilege to share the ocean with them!
Tiger sharks are intelligent and it is important to maintain eye contact with them. As long as they knew that you were watching them they would keep back about 10 feet or more. But take your eyes off them and they will get close and personal with you. They had this habit of trying to sneak up from behind so we needed to constantly be looking over our shoulders for them. A few times we had to bump them off with our cameras as they got a little too friendly. Perhaps not for most people, but it is very cool and surreal to be face to face with a 1400 pound tiger shark! You can’t help wonder what they are thinking as they swim by and stare you down.
Strange to be photographing lions and leopards in the Serengeti National Park in Africa one week and then photographing sharks in the Bahamas about a week later! We departed from West Palm Beach, Florida and headed to the famous “Tiger Beach” off of Grand Bahamas Island in hopes of finding tiger sharks. The Dolphin Dream, a 83 foot ocean expedition liveaboard, was our home for a week and we were well looked after by Captain Scott, Gerard, Shane & Heidi. We sailed through the night, cleared customs in the Bahamas in the morning and headed to a spot to do a few checkout dives in the afternoon to make sure our gear was working fine. It wasn’t long before we were taking photos of lemon sharks which commonly inhabit this area. Day 1 was all about lemon sharks.
Sharks are opportunistic feeders and lemon sharks are no exception. They are slowly swimming about searching for food but once it appears they quickly shift gears and the action can get lively. These sharks discovered food in the sand and the competition to get there first is fierce. Notice a second shark below the first one in the second photograph.
Lemon sharks are easy to identify as the first and second dorsal fin (the fins on top of their backs) are almost the same size whereas most other sharks the back dorsal fin is much smaller. These sharks can reach 11 feet in length but are commonly found in the 7 to 10 foot range which are the size that we photographed. Their eyes are a bit smaller than other sharks and they often swim with their mouths partially open.
One of the new photographic techniques we are trying to master is what is called an over-under where you place your camera 1/2 in the water and 1/2 out. This captures the shark in the water and at the same time shows the sky. We tried these as the sun was going down at the end of the day. It gives a very unique and different perspective of these lemon sharks. Not bad photos for our first attempt at “lemon-snaps”! Thanks to Terry Steeley of In The Blue Photography for all his advice about this technique.