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.
We arrived at this dry riverbed at just the right time to see this small herd of elephants. The rains were late and had not arrived in the Serengeti yet. After a few minutes, it became apparent why they were here. In the photo below you will notice a small hole in the sand about the width of their foot. Inside there is water.
We assume that the elephants have dug this hole themselves into the dry riverbed. The Serengeti can be a tough place to live in and animals must be innovative to survive. The adults will pass these skills onto the young calves.
Elephants have a wonderful group dynamic. They work collectively for the survival of the herd. As large as they are they are amazing coordinated and use their feet and trunks to perform tasks that you would think they would be incapable of. However, if you are a young calf, drinking all that water can be exhausting and sometimes you just need to get off your feet.
Fortunately, we were able to spend about 20 minutes with this herd before they had all drank from the water hole and began moving on. This group of seven consisted of 2 calves, juveniles (male and female) and adults. We never get tired of seeing and photographing elephants.
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.
There is so much expression in the eyes of a primate and you have to wonder what is going through his mind. This male Olive baboon was beginning to tire and was looking to get some sleep. With us nearby he was unwilling to close his eyes. We assume as soon as we left he closed those expressive eyes and got some deserved sleep.
Of course, if you have recently been born into this wonderful world then you have little use for sleep and would rather explore this new and curious planet. Everything is new, exciting and interesting so why sleep? This young Olive baboon was fascinating to observe and proved to be very photogenic and interested in us. Mom, however, is never far away. She is allowing her baby to explore and learn about this new environment but within limits. Should this calm situation change then she will immediately intervene to protect her baby.
Of course, the male baboon is really in charge of the entire encounter. Here he is grooming the female and picking off insects and parasites. Just below his eye is a wound probably received from a fight with another male baboon. It is a tough job being a male baboon and protecting your status as the dominant male.
Our first liveaboard experience was to Guadalupe Island off Mexico in the Pacific Ocean. The sea conditions were rough with waves 7-9 feet and many people were very seasick. The good news is that we handled the conditions quite well and just felt a bit nauseated. It proved to us that we could handle very adverse sea conditions. The 400 km (250 mile) trip started from Ensenada, Mexico and took about 24 hours to cross on the 33 meter (110 foot) vessel called the Sea Escape. Guadalupe Island is a volcanic island and home to some very large great white sharks (Carcharodon carcharias).
The great white shark, also called the white shark, can grow extremely large with some females capable of reaching 6+ meters (20 feet). As the females mature their girth increases considerably for every foot of growth. It was hard to imagine a 1900 kg (4,000 pounds) great white shark swimming a meter or two away from us and we had big expectations. Sadly, the largest shark we experienced was about 4 meters (12-13 feet). Certainly, not a monster female but a very large shark none the less.
Our first experience with great white sharks was in South Africa but the water was not very clear (green water) so it was difficult to get good pictures. As our photographs show, Guadalupe is a great place to photograph these majestic creatures. We will certainly do Guadalupe island again with hopes of photographing a massive female.
Our previous posts on the Revillagigedo Archipelago, also called the Socorro islands, have included the giant mantas(Manta birostris), whitetip reef sharks(Triaenodon obesus), and silky sharks (Carcharhinus falciformis). Although Galapagos sharks (Carcharhinus galapagensis) are fairly common especially at Roca Partida, we did not have any encounters with them there. However, on one dive we did come across a few juveniles at Socorro island and this gave us an opportunity to photograph this species.
Older sharks of all species have very scarred bodies which are simply a result of surviving in a dangerous ocean environment. However, these juvenile Galapagos sharks, which were about a meter (2-3 feet) in length, had skin with very few blemishes. Adult Galapagos sharks can reach 3 meters (9-10 feet) in length.