Biologists have discovered a new possible method by which elephant sealsfind their prey.
Southern elephant seals are not like whales that use echolocation to find their prey, or penguins that rely on smell; in fact, researchers had little idea as to how they found their food in the dark deep sea where they forage.
The seals prey primarily on lanternfish, which are bioluminescent. The fish glow as a method of communication and as a way to hide from or distract predators.
Researchers tagged several seals with devices that recorded temperature, depth, level of light and duration of dives and then analyzed data from 3,386 dives. The researchers found that elephant seals locate lanternfish through sight, using the bioluminescence to guide them to good foraging areas.
“The initial topic of the study was absolutely not dedicated to bioluminescence,” explained researcher Jade Vacquié-Garcia, a marine biologist at the Center for Biological Studies of Chize in France. “The light sensor was originally aimed to see if there was a link between the depth of penetration of light from above and how productive a depth was.”
- You can read more from Ocean Leadership here: Seals May Let Bioluminescence Fish Lead Them to Prey in Dark.
- You can read the full report, published in PLoS ONE here: Foraging in the Darkness of the Southern Ocean: Influence of Bioluminescence on a Deep Diving Predator.
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