Stalked Jellyfish Depastrum cyathiforme (Illustration by marine biologist Philip Henry Gosse)

Aaargh! I accidentally posted this yesterday, so here it is again today…

Dear Readers, with species going extinct almost before we can put a name to them, it is such a pleasure to announce that a stalked jellyfish, thought to be extinct worldwide for the past 50 years, was rediscovered by amateur naturalist Neil Roberts back in 2023. The last time the jellyfish had been seen anywhere was in France in 1976, and the animal was last spotted in the UK on Lundy Island  in 1954.

Roberts was rockpooling in South Uist when he spotted what he describes as ‘a stalked jellyfish that I didn’t recognise’. He popped his newly-purchased camera into the water with ‘some trepidation’ (quite understandable) and took a few photos. These proved to be the first-ever photos taken of this particular species of stalked jellyfish. Jellyfish expert David Fenwick went back to the site this year, and found the species again, so it appears that there’s an established population in the Outer Hebrides.

What are stalked jellyfish, though? I must admit that I’d never heard of them. Like sea anemones, these jellyfish attach themselves to rock via a sucker, and then catch small crustaceans via the stinging cells in their short tentacles. This particular species is less than 5 cm tall, and has been described as ‘looking like a thistle’. You can see some of the photos taken in 2023 and 2025 here. The UK is a hotspot for stalked jellyfish (again, who knew?), and another species, the St John’s Jellyfish, is found only in the UK and Ireland.  In all, we host 10 out of the 50 known species of stalked jellyfish.

St John’s Jellyfish (Calvadosia cruxmelitensis ) Photo by David Fenwick Snr from https://www.marlin.ac.uk/species/detail/14

It appears that, like so many creatures, stalked jellyfish are particularly sensitive to water quality in general, and nutrient run-off in particular. With the waters around the far north of Scotland being some of the cleanest in the UK this may explain why these little creatures are hanging on in the Outer Hebrides, though it would be interesting to know if they’ve survived in other places but have just gone unnoticed. Their survival highlights the importance of Marine Conservation Areas, and also the importance of the amateur naturalist, who notices something unusual and takes the time and trouble to take a photo of it. One person’s curiosity, and attention to even the smallest ‘blobs of jelly’ in a rockpool, have given us all a bit of a lift. It will be interesting to know if more of this species now turn up in other locations, now that we know that looking for them isn’t a lost cause.