I have shown the two gaper shells on one post to illustrate how different they are, beginning with the Sand Gaper above.
Sand Gaper (Mya arenaria)
A large and robust bivalve, the shell is oval in shape, the anterior end rounded, the posterior end more pointed. It has concentric ridges and is off-white, grey or light brown in colour. Shell length 15cm.
The Sand Gaper burrows to a depth of 50cm into mud and sandflats, where it filters organic matter from sea water. It is often found in estuaries, and is widespread and locally common.
Blunt Gaper (Mya truncata)
A thick-shelled, robust bivalve, rectangular in shape with a truncate posterior margin. It also has numerous concentric lines and is off-white in colour. Shell length up to 70mm.
It is commonly found in estuaries where it buries itself to a fair depth. Widespread and locally common, especially on the east coast of Britain.
Photographs taken April 2013, Llandudno, Wales. Camera Nikon Coolpix P500. © Pete Hillman 2013.
The shell is a rounded-oval, although the posterior more angled. The colour is variable from pink to purple, yellow and white. Width 25mm.
It is found on the lower shore in muddy sand, and also in estuaries. Common and widespread.
Photographs taken June 2012, Llandudno, Wales. Camera Nikon Coolpix P500. © Pete Hillman 2012.
The shell of the Common Cockle is cream to pale yellow or brownish, and it has 22-28 radiating ribs crossed by prominant concentric ridges which may bare short spines. Length up to 5cm.
It is found in muddy, sandy and fine gravel shores, from the middle to lower shore. Utilising a muscular foot, it burrows up to 5cm into the sand, and when covered by water they open their shells and extend a pair of short siphons to filter-feed on zooplankton. It can live up to 10 years, and is fished commercially and prayed upon by wading birds. It is common and widespread.
Photographs of Common Cockle (Cerastoderma edule), taken August 2011, Saundersfoot, Wales. © Pete Hillman 2011. Camera used Panasonic Lumix DMC-FZ38.
The colour of the shell is pale cream or yellowish, usually marked with three prominent radiating brown bands. It is fairly thick and has fine concentric ridges. Length 4cm.
It is found buried in the lower shore to sublittoral, and it can live up to 10 years. Common and widespread on all coasts, except the south-east coast of England.
Photographs of Striped Venus Clam (Chamelea gallina), taken August 2011, Saundersfoot, Wales. © Pete Hillman 2011. Camera used Panasonic Lumix DMC-FZ38.
This mollusc has a shiny white to yellow, purple or greyish-brown slender wedge-shaped shell. Growth stages show as pale bands. The inner surfaces are tinted white, purple, yellow or orange. Length up to 38mm.
Found on the middle to lower shore where it burrows into coarse sand and lives just below the surface. The Banded Wedge Shell is a filter feeder, and when the tide is in it extracts food particles from the water via a syphon. Common and widespread on all British and Irish coasts, but less common further north on Scottish coastlines.
Photographs of Banded Wedge Shell (Donax vittatus), taken August 2011, Saundersfoot, Wales. © Pete Hillman 2011. Camera used Panasonic Lumix DMC-FZ38.
The shell is elongate, thin and brittle. There are numerous fine concentric lines, with a group of fine radiating striae. It is white or light brown, light olive or yellow. The hinge and ligament is positioned about a third of the way along the length of the mollusc. Length up to 130mm.
It burrows deeply in fine to medium course sands in the lower shore and shallow sublittoral. Found on the south-west coasts of England, Wales and Ireland.
Photographs of Bean Solen (Pharus legumen), taken August 2011, Saundersfoot, Wales. © Pete Hillman 2011. Camera used Panasonic Lumix DMC-FZ38.
Also called the ‘Blue Mussel’, the shells are dark brown, blue-black, or purple in colour. Shell length up to 10cm.
It is found middle to lower shore, and attaches itself to rocks via byssus threads. It will also find crevices in the rocks, or attach themselves to manmade structures like piers and harbour walls. They can form large beds up to 6 layers thick and covering many square kilometres. Mussels are filter feeders of plankton, pumping large amounts of water through their bodies to extract the food.
Very common and widespread all around the British coast.
This is an edible marine mussel which has been harvested by humans for centuries. They are a rich source of protein, and are very important to the marine life ecosystem.
Photographs of Common Mussel (Mytilus edulis), taken August 2011, Saundersfoot, Wales. © Pete Hillman 2011. Camera used Panasonic Lumix DMC-FZ38.
Also called the ‘Common Razor Shell’, the shell is dull white with a yellowish tinted pink or purple colour. It is a large species, long and narrow, and the largest European species of razor shell. Length up to 20mm.
It is found on the lower shore buried in a deep vertical burrow from where it filter-feeds organic detritus via a pair of short siphons. It can live up to 20 years. Common and widespread.
Photographs taken August 2011, Saundersfoot, Wales, and August 2012, Bournemouth.