Plankton are not just tiny microscopic organisms you can’t see by a naked eye. Some of them can actually grow into several meters in length, like this “Cthulhu Mothership” of Pelagia noctiluca species found by @motmot2x

Currently there are two data sets on Plankton Portal you can switch between – the original one comes from the Southern California Bight and the newer one from the Mediterranean Sea. Each of them has a different set of categories of organisms to be marked. This Field Guide will help you to learn what you’re looking at. Besides them there are plenty of mysteries hiding in the depth waiting to be discovered!

Do you like mysteries? Join us right now on Plankton Portal. We’re waiting for you with hundreds of thousands of images which haven’t been seen by a human eye yet!