This is a cautionary tale that some reckless divers learn the hard way.

I have personally swum and dived with sharks, including the nurse shark (Ginglymostoma cirratum). Sergio Diniz, in his response to a question about marine animals encountered while diving, shares his experience with these fascinating creatures.

During my dives in Mexico and along the coast of Brazil, I had the opportunity to observe nurse sharks. These sharks are bottom feeders, relatively slow swimmers, and tend to stay in shallow, warm waters, making them easily visible underwater.

Their diet consists of sea bottom dwellers like stingrays, crustaceans, and mollusks. As a result, their mouths are relatively small and located at the bottom of their heads, equipped with teeth specialized for grinding.

Unlike other sharks such as the sand tiger shark (Carcharias taurus), nurse sharks do not possess the intimidating appearance commonly associated with fearsome predators. They are generally not known to attack humans (no fatalities have been reported), but their appearance can startle people.

Unfortunately, some individuals mistakenly perceive nurse sharks as “friendly” sharks and attempt to interact with them. Due to their high tolerance for human touch, some people may start to abuse this interaction, resulting in the loss of fingers or even hands when the shark defends itself. While nurse sharks may be slow movers, they can swiftly launch themselves to capture prey, aided by the suction created by their mouth. Hence, a hand placed too close to their mouth may swiftly be drawn into the “meat grinder,” resulting in severe injuries. Once they bite, they rarely release their grip.

Nurse sharks are obligate suction feeders, capable of generating remarkably powerful suction forces, unmatched by most aquatic vertebrates. Although their small mouths limit the size of their prey, they can exhibit a suck-and-spit behavior or violently shake their heads to reduce the size of food items.

While there have been only nine recorded unprovoked attacks by nurse sharks, resulting in zero fatalities, numerous other attacks have occurred due to human provocation. One incident involved a nurse shark biting a woman, who was subsequently taken to the hospital with the shark still attached. Although nurse sharks are generally docile, their bites can be fierce.

In recent decades, there have been a total of 44 recorded provoked attacks by nurse sharks on humans, although none of these incidents have been fatal.

ADDITIONAL NOTE:

As mentioned in the article, these incidents are not “shark attacks” but rather the result of human recklessness. One should understand that when you interfere with a shark, you face the consequences. Thank you to Stefan Pociask for the reminder.