For the first time, scientists have found evidence of a battle between sharks and a squid longer than 8 meters including tentacles in the Pacific Ocean.
The giant squid's tentacles leave large sucker-shaped golf balls on the skin of a shark's white 2.1-meter-wide ocean fin. This is the first scientific evidence of the interaction between sharks and giant squid or any other similar large squid living at depths of more than 305 meters, according to research published on June 3 in the journal Fish Biology. .
Suction mark near shark's dorsal fin. (Photo: National Geographic).
In the summer of 2019, photographer Deron Verbeck saw a shark off Kona, Hawaii, with white circular markings on the flank. Given that scientists can identify sharks based on their scars, Verbeck took several photos. When reviewing on the computer, Verbeck enlarged the dot and was surprised to realize that it was a series of large suction marks.
Yannis Papastamatiou, a shark ecologist at Florida International University in Miami, saw the picture and immediately contacted Verbeck. Papastamatiou and colleagues describe this interaction in the new study. They could not conclude which squid species are the authors of suction marks because there are a number of squid species large enough to make the mark. But according to Papastamatiou, that squid must be quite large.
The finding is particularly useful for the conservation of oceanic white shark sharks, which are critically endangered due to commercial fishing and trade in shark fins. For example, knowing that white-fin sharks can feed in deep waters can help scientists advise which marine authorities need protection.
Papastamatiou emphasized that it is difficult to draw conclusions based on a photograph. The battle may break out if two predators collide, but most likely sharks swim in the squid to hunt. White fin sharks are not picky about food, they hunt a wide range of species and small squid. Although these sharks can dive deep, they mostly hunt near water. The squid may have challenged it first, but research co-author Heather Bracken-Grissom, a biologist at Florida International University, has no record of shark squid.
"It is possible that the squid was attacked by sharks and forced to defend itself , " Bracken-Grissom speculated. Based on the suction mark on the shark's skin, Bracken-Grissom speculated that the squid was at least one meter long and 8.2 meters if including tentacles. The white markings on sharks may be caused by suction at the end of the tentacle.