I love the colours, patterns and sculpted look of Turban Top Shells – Gibbula magus (Linnaeus). I found loads of them on Weymouth Beach recently. I was surprised to find them there because usually I find only Slipper Limpets. The Turban Tops were all sorts of sizes and conditions. Some were intact with beautiful red zig zag stripey patterns. Others were worn, broken and faded. Many were covered in a strange organic-looking textured reddish-brown coating.
At the top of the sandy shore there were low-lying mounds concealing an old strandline of accumulated detritus that included large quantities of well-rotted seaweed. Winter waves had been eroding these deposits away and releasing the buried Turban Tops. The whole process was being speeded up by numerous pairs of large black crows that were systematically searching the beach for food. The bird pairs had divided up the territory and were leaving no piece of debris unturned in their patch.
There are earlier posts about these shells and the animals that occupy them. Click here for more information about Turban Top Shellsin Jessica’s Nature Blog.
Revision of a post first published 6 February 2010
Weymouth is famous for its fantastic clean sandy beach. However, patches of fine shingle with gravel-sized pebbles and stones do occur here and there. It was on shingle like this that I found masses of empty Slipper Limpet shells – Crepidula fornicata (Linnaeus) – last weekend.
This type of gastropod mollusc shell seems to be the single species most likely to be found on Weymouth beach at any time of year. They get the name from their strange shape which looks a bit like a shoe or slipper. They breed very successfully in our coastal waters although they are an introduced species to the British Isles. Their presence can affect populations of our native filter-feeding mollusc species like mussels and oysters. When Slipper Limpets settle in vast numbers on other living shellfish, the huge amount of waste matter they generate can coat and suffocate the other animals beneath them, and foul hard substrates so that larvae cannot settle there.
I have talked about Slipper Limpets in previous postings – so click here if you want to see more pictures and information about Slipper Limpets on Jessica’s Nature Blog.