Nurse shark

9/17/2018

Photo credit: Force-E Photo Pro Nikole Heath.

With a scientific name that sounds like a Harry Potter spell, Ginglymostoma cirratum, is it any surprise that the origin of where the name "nurse shark" came from is a bit fuzzy? Some say it comes from the sucking sound they make when they find prey to eat and vacuum it up, which apparently sounds like a nursing baby? Others say it’s from the word nusse which means ‘cat shark,’ and another theory is that it comes from the Old English word for sea-floor shark, hurse.

Like many other “sea-floor sharks,” these slow movers can reach impressive lengths (up to 4.3 m or 14 ft). With powerful jaws filled with rows of tiny, serrated teeth, this is not a shark you want to get munched on by. Yet, many people do end up with a nurse shark on them, as they bite defensively when stepped, kissed, yanked, or otherwise bothered. Heed this warning: A nurse shark is still a shark, friends.

Why are those jaws so strong? They need to be tough to crush through the hard exteriors of shellfish and even mouthfuls of coral as they hunt for fish, shrimp, and squid on reefs. While they look a boring grey-brown color from far away, a closer look to their dermal denticles uncovers a beautiful mix of colors otherwise missed. With their square and flat head, tendrils at the end of their snout, and long body that tapers off with a long tail, they are smooth to the touch unlike many other sharks… but please don’t touch them.

Nurse sharks love warm, shallow waters and can be abundantly observed in the western Atlantic and eastern Pacific oceans. Yet, for how widely distributed they are, scientists still know little about the gene flow between these populations. They seem to have a strong site fidelity, and scientists have actually found areas off of Florida where these sharks meet time and time again to mate!

Do nurse sharks have predators? Humans! Turns out that in Brazil they are consumed by local fishermen and in Venezuela they are marketed salted and dried! They are classified as Data Deficient (DD) by the IUCN because of the little we still know about them.