Close-up of spines on Psammechinus miliaris

U is for Urchins

Tube feet on a sea urchin: Sea urchin with slender red tube feet extended between long purple spines

Empty sea urchin test Great Barrier Reef

"Sea Potato" sea urchin test without spines: The Heart Urchin known as a Sea Potato, Echinocardium cordatum (Pennant), upper surface of the empty test or shell without spines. Rhossili Bay strandline, Gower, South Wales, U.K.

Living 'Sea Potato' sea urchin, Echinocardium cordatum (Pennant), with live bivalved molluscs, Tellimya ferruginosa (Montagu), on the low tide sand at Port Eynon, Gower, South Wales, UK

Sea urchin with symbiotic molluscs: Living 'Sea Potato' sea urchin, Echinocardium cordatum (Pennant), with live bivalved molluscs, Tellimya ferruginosa (Montagu), on the low tide sand at Port Eynon, Gower, South Wales, UK

Common British sea urchin: The empty test or shell of the Heart Urchin commonly known as the Sea Potato, Echinocardium cordatum (Pennant), from Whiteford Sands strandline, Gower, South Wales. Under surface with spines still attached

Dead Heart Urchin with spines attached: Heart Urchin known as Sea Potato, Echinocardium cordatum (Pennant), empty test, upper surface, spines still attached, from Rhossili Bay, Gower, South Wales, U.K.

Living 'Sea Potato' sea urchin, Echinocardium cordatum (Pennant), showing upper surface,on the low tide sand at Port Eynon, Gower, South Wales, UK

Sea urchin shell lower surface without spines

U is for URCHINS and not anything else on Jessica’s Nature Blog. Not many sea urchin pictures but here they are. The remaining few letters of the alphabet will be similarly challenging. I wonder what I can find.

6 Replies to “U is for Urchins”

Emma Cownie says:

November 18, 2019 at 8:08 am

I always find sea urchins very appealing, I think its a combination of their varied colours and spikiness.

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Claudia McGill says:

November 18, 2019 at 10:39 am

I don’t know anything about sea urchins but your photos have made me curious. And what great images you’ve captured.

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Robert Meyrick says:

November 18, 2019 at 10:41 am

regular and irregular echinoids

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winderjssc says:

November 19, 2019 at 6:36 am

Yes, they are attractive to look at, and it’s fascinating to observe at close quarters the way their spines are arranged in a pentamerous fashion, each one attached and articulating on a small tubercle.

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winderjssc says:

November 19, 2019 at 6:37 am

Thank you, Claudia.

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winderjssc says:

November 19, 2019 at 6:42 am

Yes, the shape of the test varies quite a bit between the species even though they are all built to the same basic design with a five way pentamerous symmetry, just like other members of the Ecinodermata like starfish and sea cucumbers.

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