Marine biologist Johnny Gaskell shot this green sea turtle snacking on a jellyfish off the coast of Hook Island, Queensland, Australia, in the Great Barrier Reef.

While jellyfish tentacles can be harmful — or even deadly — for humans, because turtles are reptiles, they are scaly and therefore much less vulnerable to the small, needle-like nematocysts that jellyfish use to inject venom into victims. The only sensitive spot on the turtle is its eye, which you can see this turtle protecting by closing its eyelids and using its flipper as a shield.

The juvenile sea turtle is estimated to be between two and five years old. In the wild, sea turtles live up to 100 years. It takes between 20 and 50 years to reach sexual maturity, and the period between hatching and reaching sexual maturity is often referred to as the "lost years," because it's been historically unclear where the turtles go or what they do during this time.

As for the jellyfish, not all hope is lost. If the turtle doesn't rip it to shreds, it can regrow its tentacles and continue life in the big blue.

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