I came across this fascinating creature on a wall above the seashore in Penzance, Cornwall, in June. I've looked at dozens of websites and haven't seen anything similar. I assume it's some kind of arthropod. It was about two inches long and sat there about a minute before wandering back down the wall towards the sea. Does anybody know what it is?
This is an interesting lateral view which frustrated my search for a while as it makes the creature look slender.
I'm pretty certain that it is the largest (to around 25mm - I think 2inches may be an over estimate) British oniscid isopod (woodlouse) which lives on hard surfaces around high water mark; Ligia oceanica. It is common on all British coasts, but usually stays concealed in cracks during daylight, with the occasional foray. Try looking at night with a torch.
Thanks for posting the photo; it's good to see things from an unfamiliar angle. And of course, I'm ready to be corrected as I'm just an amateur. If you took a top view, could you post the picture?
There is a good set of marine isopod photos, including two colour variants of Ligia on the French website
I think you've hit the nail on the head! Having searched on Ligia Oceanica and Sea Slater (the common name), looked at various photos and confirmed that they have seven pairs of legs, prominent eyes and twin tails, I am certain that you are correct in your identification. I only saw it from the angle shown as the wall was very high - I could barely get my eyes over the lip, so cranked my camera up there and took the shot. The lateral view also confused my attempts at identification.
Thanks very much, and well done!
That's odd, I have just finished posting my own ID plea and now I've just seen yours!
My sighting was very similar to your picture and seen at the same type of place, but those I saw were definitely pink (like a pig and smooth like pigs)
and they had no tails/tail like appenage that I recollect. They had a slow, pottering type gait, like yours? I saw them during the day.
Also they definitely had three legs protruding from each side, no less or more, so i wonder if they were the same creatures as those you saw.
I'll keep watching, but it's good that someone else has seen something similar, as my partner never did believe me!