Underwater photographer Deron Verbeck was diving off the coast of Kona, Hawaii when he came across an oceanic whitetip shark (Carcharhinus longimanus) with unusual scarring across its head and back. This shark occurs in tropical and temperate waters worldwide from inshore areas to remote oceanic waters. Solitary and slow moving, oceanic whitetip sharks are easily identified by their long, white-tipped, rounded fins. They were once considered one of the most abundant shark species in the world but are now listed as threatened under the Endangered Species Act. Opportunistic and aggressive, they are no strangers to scars on their body by other sharks. But these marks were different.
Underwater photographer Deron Verbeck was diving off the coast of Hawaii when he spotted this ... [+]
Verbeck snapped a photo of the shark with the unusual scarring pattern of circles and dots and brought the photo to Florida International University (FIU) marine scientists Dr. Yannis Papastamatiou, Dr. Demian Chapman and Dr. Heather Bracken-Grissom. Verbeck was right to think the scars did not look like shark teeth marks, because they weren’t. Instead, they were most likely caused by the suckers from a squid’s tentacles — a rather large one.
Giant squid (Architeuthis dux) markings, beaks, and other undigested body pieces have been found in the stomachs of sperm whales before, but the FIU researchers believe this may be the first time these markings have been seen on a shark. Although no footage exists of the showdown between the shark and whatever attacked it, the marine scientists aren’t ruling out the possibility that two of the ocean’s most mysterious creatures — the oceanic whitetip and the giant squid — may have fought.
Giant squid are thought to be distributed worldwide, living deep underwater. Despite being the biggest invertebrate on Earth, they remain an elusive mystery to scientists. They certainly live up to their name, with the largest giant squid ever recorded measuring almost 43 feet (13 meters) long, possibly weighing nearly a ton. They are rarely seen alive (it was first recorded live in 2006 and in 2012 a group of scientists filmed a giant squid in its natural habitat), so most of what we know comes from dead specimens. Like other squids and octopuses, giant squid also have two eyes, a beak, eight arms, two feeding tentacles, and a funnel (also called a siphon). Their eight arms covered with serrated suckers that guide their prey from the feeding tentacles to a sharp beak that awaits in the center of their arms.
Giant squid (Architeuthis dux) markings, beaks, and other undigested body pieces have been found in ... [+]
So how did these two elusive predators meet? For over a decade, Papastamatiou and Chapman have studied the habitat use of oceanic whitetip sharks, using technology to record swim speed, acceleration and depth. The data has shown they dive very deep - sometimes up to 1,000 feet (305 meters) below the surface! Once thought as inhospitable, it seems this deep-sea habitat is a possible foraging ground for this shark species, allowing them to target prey like smaller squid. Dr. Bracken-Grissom, who was part of the research team that captured the first-ever video of a giant squid in U.S. waters, says it’s most likely the shark was on the hunt; it is unclear who was the ultimate victor, however.
The findings were recently published in the Journal of Fish Biology. But it poses more questions than answers. “This just shows that we still don’t fully understand the interactions between these big animals in the open ocean or how the shallow and deep ecosystems are connected,” Papastamatiou said.
