Nurse Sharks are a wonderful, docile species that are nicknamed the “couch potatoes of the ocean.” They are a favorite shark among divers to swim and snorkel with because you can get up close to them and still be very safe. They are also one of the most social sharks of the ocean and tend to spend time in groups just lounging on the ocean floor. They are a great species to learn about because their gentle nature and social behaviors dispel the myths that sharks are ferocious, solitary man-eaters. So here are ten interesting shark facts about this great species:
1. Scientists Aren’t Clear On Where The Name Nurse Sharks Comes From
There are a couple of theories about why these sharks are called “Nurse Sharks.” Some believe it comes from the ancient work “nusse” which means “Catshark.” While others believe the name comes from the Old English term “hurse” which means “seafloor shark.” However, other scientists believe that the name comes from the unusual sucking sound they make while hunting that resembles the suckling of a nursing baby. All of these theories are very valid and the scientific community may never know where the name came from.
2. Nurse Sharks Spend Their Days Sleeping In Cuddle Piles
Nurse Sharks are nocturnal, so they only tend to be very active at night. So they spend all day sleeping. What is really unusual about Nurse Sharks is they will slept together in very large groups. Sometimes these groups can contain up to 40 different sharks. Not only do they sleep together, they have been observed cuddling and snuggling. Scientists aren’t sure why Nurse Sharks prefer to sleep together, having a range of theories from they are very socially advanced to they sleep together as a protection from predators like Lemon and Bull Sharks.
3. Nurse Sharks Swim Very Slowly
Nurse Sharks spend a lot of their spare time just lying at the bottom of the seafloor. However, even when they do get up and move, they tend to only travel at about 1.5 mph (2.4 kph). However, when they are hunting they are capable of quick bursts of speeds that reach up to 25 mph (40 kph).
4. Nurse Sharks Low Warm Shallow Waters
Nurse sharks tend to live along the coastlines in tropical and subtropical waters. They generally spend their time in waters that are 3.2-40 ft (1-12 m) deep, though if forced to, they will hunt in deeper waters of up to 246 ft (75 m). Though it is very rare for them to hunt in deeper waters since they do not like the cold.
5. Nurse Sharks Are Pretty Large, But Not As Large As Some People Think
There have been reports of Nurse Sharks growing up to 15 ft (4.5 m) and weighing 730 lb (330 kg). However, since these reports have never been confirmed, it is assumed that most of them are either exaggerated or a case of mistaken identity because they look similar to some of the larger sharks that share their waters. However, Nurse Sharks still are a very large species of shark. They grow to 10.1 ft (3.08 m) in length and weight around 200 lb (90 kg).
6. Nurse Sharks Have Unusually Large Tail Fins
Nurse Sharks have extremely large tail fins. Their tail fins measure around 2-3 ft (0.6-0.9 m), which is one fourth of their total body length. They use this tail to help them combat their slow metabolisms. Since sharks use their tails to propel themselves through the water, the large tail of the Nurse Shark helps them swim while expelling less energy.
7. Nurse Sharks Have A Very Diverse Diet
Since Nurse Sharks tend to inhabit environments like coral reefs, mangrove islands, and sand flats where food is in an abundance, they tend to eat a lot of different kinds of prey. Nurse Sharks eat fish, other sharks, shrimp, sea urchins, octopus, stingrays, sea snakes, molluscs, tunicates, and crustaceans. So basically, like a typical couch potato, they’ll laze around and eat anything.
8. Nurse Sharks Are The Most Common Species Of Shark In The Tropics
Nurse Sharks are very populous compared to other tropical sharks. Since they have extremely low metabolisms, tending to eat 18% of other what comparable sharks eat, there can be more of them located in a smaller area without draining the food resources. Also, even though their mating cycle only happens once a year and their gestation period takes 18 months, they give birth to large litters of 21-29 pups. So they can populate areas very quickly when not under threat.
9. Nurse Sharks Are Under Threat From Humans
Nurse Sharks are often a target of commercial fishing. Their flesh is considered so delicious it is often consumed raw. It also has very tough skin so fisherman prize Nurse Sharks for their leather. Plus, since Nurse Sharks are both slow and docile, they are easy to hunt and trap. Fortunately, in some areas they are protected because they attract ecotourism revenue. However, like all sharks their numbers are dwindling.
10. Nurse Sharks Present No Threat To Humans
One of the main reasons why divers love to swim with Nurse Sharks is they are not typically aggressive towards humans. There have only been 44 recorded Nurse Shark attacks on humans in history. Most of these attacks were provoked by the humans getting too close or prodding the shark and none of them were fatal. In general, Nurse Sharks will leave humans alone if humans leave them alone.
These are just ten of the interesting shark facts about this docile species. As a favorite of divers and snorkelers, humans interact with them quite frequently. So we know quite a bit about the species compared to other sharks. Nurse Sharks are a really unique species of shark. Their docile, social nature breaks the myths of the ferocious, evil predators and instead helps us understand that there are many different kinds of sharks that swim in our oceans.