Take the 2-minute tour ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

I filmed the creatures below this August in the Mediterranean (specifically, the port of Fornells in Minorca of the Balleares). The images were taken from a boat moored just outside the harbor and flowting above a field of posidonia in case that is relevant.

There were many of them and they were whizzing about at high speed:

enter image description here enter image description here

This is to give you an idea of the scale. The jellyfish on the right was about the size of half a tennis ball.

enter image description here

They were a very strange sight since there were so many of them and moving so fast. You can see a video of them in motion here:


The image quality is not very good but you can see how fast the things were moving. So, any idea what these are? I am assuming they are larvae of something or other but what?

share|improve this question
add comment

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.