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Mail Buoy: May 17

A sample from the Twilight Zone includes an Atolla jelly (far right) and other invertberates. Photo by Marley Parker, @Woods Hole Oceanographic Institution


Hi, we are students in Ms. Sheild's class, and we saw the red jellyfish on the Day 8 post. We were wondering, is that jellyfish dangerous or poisonous because it is colorful and red? Thank you.

-Alex M. and Saayali J., Clarke Middle School


Good Question! On land, red is considered a bright color, but in the ocean, red pigment is the complete opposite. The high frequency of red wavelengths means that this color attenuates—or disappears—over the shortest distance in water. So even though this Atolla jellyfish appears red to us on land (where it's bright), it can hide in plain sight in the twilight zone!

Several different ocean twilight zone animals use this adaptation to avoid predators. You can read more about the Atolla jellyfish here.

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