Like colourful butterflies on the sand, the paired valves of the Banded Wedge Shell are one of the common and attractive finds on Rhossili beach, Gower. On the outer surface they are often bright yellow while the inner surface is frequently a lovely lilac or purple colour.
The empty shells can occur in large numbers on the strandlines but, if you look carefully underfoot at low tide level, you can find the animals alive in the wet sand. Typically, part of the shell protrudes above the surface; it may be obscured by sand.
The texture of the sand varies from fine and compact with a smooth surface texture to patches where the sand grains appear coarser and the surface is an uneven texture looking a bit like lumpy porridge.
Occasionally, the Banded Wedge Shells are found entirely exposed, lying in the surface water. In the picture below you can see the soft translucent fleshy foot and the siphons partially extended between the hard shiny shell. The large muscular foot is used to rapidly draw this bivalve down into the safety of the wet sediments if it is disturbed – either by the incoming surf or passing feet.
If you wait patiently and watch a partially buried Banded Wedge Shell, you may witness the cyclical retraction and subsequent extension of the paired tubular siphons as they squirt out water. In the photograph below the siphons are fully extended and have just evacuated.
Revision of a post first published 29 August 2009
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