A Fever of Stingrays
Gregory Alan Bolcer stashed this in All the world's a stage
Stumbled on this...so many of them....though as the commenter points out, it's not a school. It's called a "Fever" of stingrays, not a MotherF....
Wow! so many, wonder why they do it? Is it breeding?
I can't even speculate....no wait I can. ;-) Sex, death, or food.
I think you have all the bases covered there ;)
They're not stingrays; they're devil rays:
These are not stingrays of any sort, but Mobula munkiana, or Munkiana Devil Rays. They are much more similar to Manta rays, though slighty smaller.
Rays of the Mobula genus do not have poisonous barbs (stingers), so they often travel in large schools to create safety in numbers. They are extremely gentle and unbelievably fascinating creatures.
More from Reddit:
You can swim with them! The rays of the genus are intensely curious (Mobula have some of the highest brain-to-bodyweight ratio of any fishes), and they often will follow swimmers and explore passing boats, even breaching to get a better view (like the ray on the right side of the school is doing). They are very intelligent, but unfortunately we don't really know how intelligent - they don't do very well in captivity.
And look how they jump:
they don't even have poisonous barbs! wow, i want to get all up in that fever of devil rays!
(and i love the video of them flying, adam. they look so joyful!)