Recently, I had an amazing opportunity to try out my brand new Foldscope that I got through the Kickstarter campaign. I was on holiday near XaiXai in Mozambique and took my Foldscope to the beach to see what I could find. Two different cnidarian species had washed up on the beach: blue bottles (also known as Portuguese man o’ war; Physalia physalis ) and by-the-wind-sailor ( Velella vellela ). I was really excited  to see if I could find their stinging cells, also known as nematocysts. I collected my samples in some sea water and used the forceps in the deluxe Foldcsope kit to handle these little creatures to avoid getting stung.

A couple blue bottle samples in a Foldscope bag, and a cutting from one of their tentacles mounted on a slide with the PVC coverslip:

It was amazing to see the beautiful rounded nematocysts arranged on  the bulbous tubular tentacle:

And I could also watch liquid circulating inside the tentacle:

The by-the-wind-sailor was even more intriguing. I cut off and mounted a few tentacles from its underside and was astounded by their amazing colours… a mixture of yellows, greens and blues! Similarly shaped nematocysts were also present. It was interesting to compare the tightly coiled, bulbous structure of the blue bottle tentacle to the by-the-wind-sailors more relaxed tentacle structure.

It was also possible to see liquid and particles (food?) circulating inside these tentacles:

When I cut off the by-the-wind-sailor tentacles I must have cut through one of the gonozooids as I think I released some eggs:

My Foldscope is definitely coming to the beach with me again in the future!