Nurse Shark

Although how they got the name “Nurse shark” is unknown, they are called “couch potatoes” due to their lazy, peaceful behavior and their habit of sucking and eating up tiny living creatures on the ocean floor as they swim past.

Although they are of the shark species, these ocean dwellers are different from their aggressive, scary-looking counterparts. But just what makes them so unique? Let’s find out.

Appearance

Nurse sharks can be easily identified from the rest of the shark species due to their different appearance. They have wide body with a small rectangular mouth and their dorsal fins are rounded than sharp. Their skin is smoother than most sharks and their color leans towards yellowish-brown rather than grey. They can grow up to 9 feet long and have two sensory organs called ‘barbels’ that grow under their mouth. These barbels are their “taste buds” and they drag it across the ocean floor to find small fishes and crabs hiding in the sand.

Characteristics

Nurse Sharks are generally harmless to humans and are slow-moving ocean-floor dwellers. They are nocturnal predators, but they are very social. During the day, they rest on sand or between reef crevices with piles of around 40 other Nurse Sharks or similar-sized sharks. This also means that, unlike the other sharks that need to constantly swim to breathe, Nurse Sharks can breathe even when staying still. This is known as Buccal Pumping. They use oral muscles to actively suck water into their mouth and this supplies oxygen into their gills.

Habitat

The Nurse Sharks are usually found in the tropical and subtropical warm waters in the Atlantic and Pacific oceans. They live in depths ranging from 3 to 250 feet. In the Atlantic Ocean, they are found from Rhode Island to southern Brazil, the Caribbean, and the Gulf of Mexico. In the eastern Atlantic, they can be spotted from the Cape Verde Islands to the African coast. These sharks are usually spotted roaming around the coral reefs or resting on salt flats and between mangrove islands. They also preferably exist next to human activity.

Diet

Although peaceful, Nurse Sharks are carnivorous in nature but without being violent. They usually feed on shrimps, small octopuses, lobsters, sea urchins, squid, snails, catfishes, mullets, puffers, and stingrays. Their mouths allow them to suck and feed at an incredible speed. Their nightly hunts are also a major factor in their fast-eating habits as most of their prey are asleep and unguarded at overnight hours. They are also known to bite and chew on corals as well.

Reproduction

Female Nurse Sharks often mate with more than one male, with the mating season starting in May and lasting till July. Numerous male Nurse sharks will attempt to mate with a single female simultaneously by biting her pectoral fin and shoving her to one side.  The female sharks have a six-month gestation period and then give birth to around 40 young ones. The baby sharks, from a single birth, could have up to six different fathers.  Once the birthing is over, the mother won’t mate for another 18 months. She would usually stay in shallow waters with her pectoral fins buried in the sand to avoid the males.

Population

Although the conservation status of the Nurse Sharks is unknown since the data of their numbers are insufficient, they are said to be under threat from humans since they are a target for commercial fishing. Their flesh is considered to be delicious, and their skin is used for leather. Since they are slow, docile, and live near humans, they are easy to hunt. They are protected in some areas due to ecotourism, but like the overall state of the ocean floor, the numbers of these sharks are starting to waver.

Fun Facts about Nurse Sharks

• They “walk” across the ocean floor – Nurse Sharks hunt within 65 feet of the ocean floor around coral reeves and coastal shelves. When they are on the lookout for prey, they move at a very slow pace by using their pectoral fins to “walk” on the sandy floor instead of swimming around.

• The origin of the name is unknown – Why they are called “Nurse Sharks” is still unknown to this day. Some theories say that it could be because of the sound they make when they suck up their food, much like a nursing baby. Other theories suggest that the name was derived from the archaic word “nusse” which means “catfish.” The most likely theory, though, is that the name came from the word “hurse” of Old English.

• They are harmless to humans, and even if they attack, it’s not fatal – Although sharks are generally misunderstood to be aggressive and dangerous, Nurse Sharks go a little further into the total “no harm” behavior. Even if you are in the ocean diving, swimming, or exploring and there is a Nurse Shark nearby, it will be completely harmless. Even if, for some reason, they are provoked and attacked, their bite isn’t powerful enough to be fatal.

• Whale Sharks are their relatives – These huge beauties are the biggest sharks living on earth, and they are related to the Nurse Sharks. They are both members of the Orectolobiformes species. They both eat by suction and live in warm tropical waters. They also have similar mouths that are unlike the rest of the shark species.  

• They are known to be lazy – Nurse Sharks are nocturnal and feed during the night, but most of the day, they are usually seen lazy-ing around by lounging in the sand or crevices of coral reeves in a cuddle pile with other Nurse Sharks.

FAQs about the Nurse Shark