Unexpected Encounter Reveals Bioluminescence Strategy
In an extraordinary encounter, a rare and enigmatic giant squid attacked an underwater camera in the depths of the ocean, providing researchers with a glimpse into how the creature uses its massive bioluminescent organs for predation.
Attack on Camera
The giant squid's surprise attack occurred in the Pacific Ocean, approximately 1,000 meters beneath the surface. Researchers from the Minderoo Foundation and the University of Western Australia (UWA) Oceanographer Team recorded the incident using a baited camera deployed in the waters near the Samoan Passage, a deep-water trench north of Samoa.
The Dana Octopus
The squid encountered by the researchers is known as the Dana octopus (Taningia danae), a member of the Octopoteuthidae family that preys on deep-sea fish, crustaceans, and other squid species. Octopoteuthids have eight arms, hence the classification as an octopus, and possess two long tentacles when juvenile that are lost in adulthood.
Dana octopuses are known for their impressive size. The largest recorded specimen, a female, measured 2.3 meters in length, according to a 2003 study. The squid in the new footage was approximately 75 centimeters long, according to UWA.
Emerging from the darkness, the squid lunged at the camera, wrapping its arms around the device before quickly retreating. Prior to attaching itself to the camera, the squid deployed a pair of light-producing organs called photophores located at the tips of two of its arms.
Bioluminescence for Predation
Dana octopuses' photophores emit light through a chemical reaction. These organs are the largest among animals but have rarely been observed in action, according to Heather Stewart, an adjunct oceanographer at UWA. Researchers believe the photophores may serve to disorient prey in the darkness of the deep sea, as well as for communication between individuals. The squid's control over flashing patterns by manipulating eyelid-like membranes surrounding the photophores further supports this hypothesis.
Stewart believes the squid in the footage attacked the camera because it mistook it for prey and attempted to startle it with its bioluminescence.
Limited Knowledge of Dana Octopus
Researchers have limited knowledge about the behavior of Dana octopuses due to their elusive nature. Most knowledge has been gathered from beached specimens, bycatch, or stomach contents of whales, said Jamieson, the Director of UWA's Centre for Marine Futures. The first live specimen was observed by researchers 19 years ago using a similar camera system.
Summary
The unexpected encounter between a giant Dana octopus and an underwater camera has provided researchers with valuable insights into the predatory strategies and bioluminescent capabilities of this enigmatic deep-sea creature. Despite their rarity, Dana octopuses play a significant role in the deep-sea ecosystem, and their elusive nature continues to fuel scientific curiosity.