There are around 400 species of sharks living beneath the ocean’s rippling surface … that we know of. Humans have only explored about two percent of the world’s massive expanse of saltwater, so it’s fairly safe to say there’s a predator or two out there we haven’t met yet.
Like any other animal, each species of shark has its own unique set of habits, characteristics, and preferences. Whale sharks, for example, glide through warm waters at just 3 mph, periodically opening their impossibly large mouths to feed on plankton and other minuscule fish.
Meanwhile, shortfin makos jet through the clear blue sea, reaching speeds exceeding 30 mph. They hunt cephalopods and bony fish alike, lunging upward to tear off chunks of flesh before their prey even knows they’re there.
Then there’s the nurse shark, which, as researchers recently discovered, is apparently perfectly capable of walking and performing headstands on the sea floor when the mood strikes.
In a new study published in Environmental Biology of Fishes, scientists revealed the results of their research. Nurse sharks can produce all sorts of bizarre stunts to obtain food.
Together with the nonprofit Beneath the Waves, scientists began by installing underwater cameras off the coast of Turks and Caicos. They then documented the wide range of strange behaviors exhibited by typically slow, sedentary species in their quest for a hearty meal.
Nurse Sharks Capable of Performing Acrobatics to Get Food
As their subjects showed, nurse sharks use a combination of vertical feeding (headstands), ventral feeding (belly rolls), and “pectoral positioning” to get their food. That last one is the movement that closely mirrors walking, the hungry fish using its fins to crawl along the sea floor toward its food.
“During this behavior, the shark bends or arches one or both pectoral fins [and] touches the tops of the fins to the seafloor,” Beneath the Waves wrote beneath the video of the acrobatic nurse shark. “[It] then pushes off of the seabed to maneuver into a more favorable position to suction out food.”
“Pectoral positioning has previously only been seen in three families of elasmobranchs (sharks, skates, and rays) that include bamboo sharks, sleeper rays, and smooth skates, making this a notable discovery.”
“These feeding behaviors show that nurse sharks are adapted to feed on different prey across a variety of habitats,” said lead study author Kristian Parton. “Our footage suggests nurse sharks may do something similar on the sea floor.”
“This work illustrates the immense behavioral adaptability of coastal shark species,” added Dr. Oliver Shipley, a senior research scientist at Beneath the Waves.
Before now, research surrounding nurse sharks has largely focused on reproduction, scientists say. Now, however, they’re delving deeper into the fascinating species. “Despite their widespread nature, we know comparatively little about nurse shark behavior relative to other coastal species,” Shipley continued. “So this study provides an important step to further understanding their ecological role.”